caver.utils
caver-js utility APIs.
caver.utils provides utility functions.
randomHex
caver.utils.randomHex(size)The randomHex library to generate cryptographically strong pseudo-random HEX strings from a given byte size.
Parameters
size
number
The byte size for the HEX string, e.g., 32 will result in a 32-byte HEX string with 64 characters prefixed with "0x".
Return Value
string
The generated random HEX string.
Example
> caver.utils.randomHex(32)
'0x861b56754dba7769f9740c3ad70b4694aa24d604c1dba3bac7ec45978927b8de'
> caver.utils.randomHex(4)
'0x5641d6ce'
> caver.utils.randomHex(2)
'0xf058'
> caver.utils.randomHex(1)
'0x7c'
> caver.utils.randomHex(0)
'0x'_
caver.utils._()The underscore library for many convenient JavaScript functions.
See the underscore API reference for details.
Example
> var _ = caver.utils._
> _.union([1,2],[3])
[1,2,3]
> _.each({my: 'object'}, function(value, key){ ... })
...toBN
caver.utils.toBN(number)Safely converts any given value (including BigNumber.js instances) into a BN.js instance, for handling big numbers in JavaScript.
Parameters
number
string | number
number to convert to a big number.
Return Value
Object
The BN.js instance.
Examples
> caver.utils.toBN(1234).toString()
'1234'
> caver.utils.toBN('1234').add(caver.utils.toBN('1')).toString()
'1235'
> caver.utils.toBN('0xea').toString()
'234'isBN
caver.utils.isBN(bn)Checks if a given value is a BN.js instance.
Parameters
Return Value
boolean
true if a given value is a BN.js instance.
Example
> var number = new caver.utils.BN(10)
> caver.utils.isBN(number)
trueisBigNumber
caver.utils.isBigNumber(bignumber)Checks if a given value is a BigNumber.js instance.
Parameters
Return Value
boolean
true if a given value is a BigNumber.js instance.
Example
> var number = new caver.utils.BigNumber(10)
> caver.utils.isBigNumber(number)
truesha3
caver.utils.sha3(str)
caver.utils.keccak256(str) // ALIASCalculates the sha3 of the input.
NOTE: To mimic the sha3 behavior of Solidity use caver.utils.soliditySha3.
Parameters
str
string
A string to hash.
Return Value
string
The result hash.
Example
> caver.utils.sha3('234') // taken as string
'0xc1912fee45d61c87cc5ea59dae311904cd86b84fee17cc96966216f811ce6a79'
> caver.utils.sha3(new caver.utils.BN('234')) // utils.sha3 stringify bignumber instance.
'0xc1912fee45d61c87cc5ea59dae311904cd86b84fee17cc96966216f811ce6a79'
> caver.utils.sha3(234)
null // can't calculate the has of a number
> caver.utils.sha3(0xea) // same as above, just the HEX representation of the number
null
> caver.utils.sha3('0xea') // will be converted to a byte array first, and then hashed
'0x2f20677459120677484f7104c76deb6846a2c071f9b3152c103bb12cd54d1a4a'soliditySha3
caver.utils.soliditySha3(param1 [, param2, ...])Calculates the sha3 of given input parameters in the same way solidity would. This means arguments will be ABI converted and tightly packed before being hashed.
Parameters
paramX
Mixed
Any type, or an object with {type: 'uint', value: '123456'} or {t: 'bytes', v: '0xfff456'}. Basic types are autodetected as follows:
- string non numerical UTF-8 string is interpreted as string.
- `string
Return Value
string
The result hash.
Example
> caver.utils.soliditySha3('234564535', '0xfff23243', true, -10)
// auto detects: uint256, bytes, bool, int256
'0x3e27a893dc40ef8a7f0841d96639de2f58a132be5ae466d40087a2cfa83b7179'
> caver.utils.soliditySha3('Hello!%') // auto detects: string
'0x661136a4267dba9ccdf6bfddb7c00e714de936674c4bdb065a531cf1cb15c7fc'
> caver.utils.soliditySha3('234') // auto detects: uint256
'0x61c831beab28d67d1bb40b5ae1a11e2757fa842f031a2d0bc94a7867bc5d26c2'
> caver.utils.soliditySha3(0xea) // same as above
'0x61c831beab28d67d1bb40b5ae1a11e2757fa842f031a2d0bc94a7867bc5d26c2'
> caver.utils.soliditySha3(new caver.utils.BN('234')) // same as above
'0x61c831beab28d67d1bb40b5ae1a11e2757fa842f031a2d0bc94a7867bc5d26c2'
> caver.utils.soliditySha3({type: 'uint256', value: '234'})) // same as above
'0x61c831beab28d67d1bb40b5ae1a11e2757fa842f031a2d0bc94a7867bc5d26c2'
> caver.utils.soliditySha3({t: 'uint', v: new caver.utils.BN('234')})) // same as above
'0x61c831beab28d67d1bb40b5ae1a11e2757fa842f031a2d0bc94a7867bc5d26c2'
> caver.utils.soliditySha3('0x407D73d8a49eeb85D32Cf465507dd71d507100c1')
'0x4e8ebbefa452077428f93c9520d3edd60594ff452a29ac7d2ccc11d47f3ab95b'
> caver.utils.soliditySha3({t: 'bytes', v: '0x407D73d8a49eeb85D32Cf465507dd71d507100c1'})
'0x4e8ebbefa452077428f93c9520d3edd60594ff452a29ac7d2ccc11d47f3ab95b' // same result as above
> caver.utils.soliditySha3({t: 'address', v: '0x407D73d8a49eeb85D32Cf465507dd71d507100c1'})
'0x4e8ebbefa452077428f93c9520d3edd60594ff452a29ac7d2ccc11d47f3ab95b' // same as above, but will do a checksum check, if its multi case
> caver.utils.soliditySha3({t: 'bytes32', v: '0x407D73d8a49eeb85D32Cf465507dd71d507100c1'})
'0x3c69a194aaf415ba5d6afca734660d0a3d45acdc05d54cd1ca89a8988e7625b4' // different result as above
> caver.utils.soliditySha3({t: 'string', v: 'Hello!%'}, {t: 'int8', v:-23}, {t: 'address', v: '0x85F43D8a49eeB85d32Cf465507DD71d507100C1d'})
'0xa13b31627c1ed7aaded5aecec71baf02fe123797fffd45e662eac8e06fbe4955'isHex
caver.utils.isHex(hex)Checks if a given string is a HEX string.
Parameters
hex
string
The given HEX string.
Return Value
boolean
true if a given parameter is a HEX string.
Example
> caver.utils.isHex('0xc1912')
true
> caver.utils.isHex('c1912')
true
> caver.utils.isHex('0xZ1912')
false
> caver.utils.isHex('Hello')
falseisHexStrict
caver.utils.isHexStrict(hex)Checks if a given string is a HEX string. Difference to caver.utils.isHex is that it expects HEX to be prefixed with 0x.
Parameters
hex
string
The given HEX string.
Return Value
boolean
true if a given string is a HEX string.
Example
> caver.utils.isHexStrict('0xc1912')
true
> caver.utils.isHexStrict('c1912')
false
> caver.utils.isHexStrict('0xZ1912')
false
> caver.utils.isHex('Hello')
falseisAddress
caver.utils.isAddress(address)Checks if a given string is a valid Klaytn address. It will also check the checksum if the address has upper and lowercase letters.
Parameters
address
string
An address string.
Return Value
boolean
true if a given string is a valid Klaytn address.
Examples
> caver.utils.isAddress('0xc1912fee45d61c87cc5ea59dae31190fffff232d')
true
> caver.utils.isAddress('c1912fee45d61c87cc5ea59dae31190fffff232d')
true
> caver.utils.isAddress('0XC1912FEE45D61C87CC5EA59DAE31190FFFFF232D')
true // as all is uppercase, no checksum will be checked
> caver.utils.isAddress('0xc1912fEE45d61C87Cc5EA59DaE31190FFFFf232d')
true
> caver.utils.isAddress('0xC1912fEE45d61C87Cc5EA59DaE31190FFFFf232d')
false // wrong checksumtoChecksumAddress
caver.utils.toChecksumAddress(address)Converts an upper or lowercase Klaytn address to a checksum address.
Parameters
address
string
An address string.
Return Value
string
The checksum address.
Examples
> caver.utils.toChecksumAddress('0xc1912fee45d61c87cc5ea59dae31190fffff232d')
'0xc1912fEE45d61C87Cc5EA59DaE31190FFFFf232d'
> caver.utils.toChecksumAddress('0XC1912FEE45D61C87CC5EA59DAE31190FFFFF232D')
'0xc1912fEE45d61C87Cc5EA59DaE31190FFFFf232d' // same as abovecheckAddressChecksum
caver.utils.checkAddressChecksum(address)Checks the checksum of a given address. Will also return false on non-checksum addresses.
Parameters
address
string
An address string.
Return Value
boolean
true when the checksum of the address is valid, false if it is not a checksum address, or the checksum is invalid.
Examples
> caver.utils.checkAddressChecksum('0xc1912fEE45d61C87Cc5EA59DaE31190FFFFf232d')
truetoHex
caver.utils.toHex(mixed)Converts any given value to HEX. The numeric strings will be interpreted as numbers. Text strings will be interpreted as UTF-8 strings.
Parameters
mixed
string | number | BN | BigNumber
The input to convert to HEX.
Return Value
string
The resulting HEX string.
Examples
> caver.utils.toHex('234')
'0xea'
> caver.utils.toHex(234)
'0xea'
> caver.utils.toHex(new caver.utils.BN('234'))
'0xea'
> caver.utils.toHex(new caver.utils.BigNumber('234'))
'0xea'
> caver.utils.toHex('I have 100€')
'0x49206861766520313030e282ac'hexToNumberString
caver.utils.hexToNumberString(hex)Returns the number representation of a given HEX value as a string.
Parameters
hexstring
string
A HEX string to be converted.
Return Value
string
The number as a string.
Examples
> caver.utils.hexToNumberString('0xea')
"234"hexToNumber
caver.utils.hexToNumber(hex)Returns the number representation of a given HEX value.
NOTE: This is not useful for big numbers, rather use caver.utils.toBN.
Parameters
hexstring
string
A HEX string to be converted.
Return Value
number
The number representation of a given HEX value.
Examples
> caver.utils.hexToNumber('0xea')
234numberToHex
caver.utils.numberToHex(number)Returns the HEX representation of a given number value.
Parameters
number
string | number | BN | BigNumber
A number as string or number.
Return Value
string
The HEX value of the given number.
Examples
> caver.utils.numberToHex('234')
'0xea'hexToUtf8
caver.utils.hexToUtf8(hex)
caver.utils.hexToString(hex) // ALIASReturns the UTF-8 string representation of a given HEX value.
Parameters
hex
string
A HEX string to convert to a UTF-8 string.
Return Value
string
The UTF-8 string.
Examples
> caver.utils.hexToUtf8('0x49206861766520313030e282ac')
'I have 100€'hexToAscii
caver.utils.hexToAscii(hex)Returns the ASCII string representation of a given HEX value.
Parameters
hex
string
A HEX string to convert to an ASCII string.
Return Value
string
The ASCII string.
Examples
> caver.utils.hexToAscii('0x4920686176652031303021')
'I have 100!'utf8ToHex
caver.utils.utf8ToHex(str)
caver.utils.stringToHex(str) // ALIASReturns the HEX representation of a given UTF-8 string.
Parameters
str
string
A UTF-8 string to convert to a HEX string.
Return Value
string
The HEX string.
Examples
> caver.utils.utf8ToHex('I have 100€')
'0x49206861766520313030e282ac'asciiToHex
caver.utils.asciiToHex(str)Returns the HEX representation of a given ASCII string.
Parameters
str
string
An ASCII string to convert to a HEX string.
Return Value
string
The HEX string.
Examples
> caver.utils.asciiToHex('I have 100!')
'0x4920686176652031303021'hexToBytes
caver.utils.hexToBytes(hex)Returns a byte array from the given HEX string.
Parameters
hex
string
A HEX string to be converted.
Return Value
Array
The byte array.
Examples
> caver.utils.hexToBytes('0x000000ea')
[ 0, 0, 0, 234 ]bytesToHex
caver.utils.bytesToHex(byteArray)Returns a HEX string from a byte array.
Parameters
byteArray
Array
A byte array to convert.
Return Value
string
The HEX string.
Examples
> caver.utils.bytesToHex([ 72, 101, 108, 108, 111, 33, 36 ])
'0x48656c6c6f2124'convertToPeb
caver.utils.convertToPeb(number [, unit])Converts any KLAY value into peb.
NOTE: "peb" is the smallest KLAY unit, and you should always use "peb" as the unit of KLAY. Convert to "KLAY" only for display reasons.
Parameters
number
string | number | BN
The value.
unit
string
(optional, defaults to "KLAY") The unit of KLAY to convert from. number will be multiplied by one of the following multipliers for the unit provided:
- peb: '1'
- kpeb: '1000'
- Mpeb: '1000000'
- Gpeb: '1000000000'
- Ston: '1000000000'
- uKLAY: '1000000000000'
- mKLAY: '1000000000000000'
- KLAY: '1000000000000000000'
- kKLAY: '1000000000000000000000'
- MKLAY: '1000000000000000000000000'
- GKLAY: '1000000000000000000000000000'
Return Value
string | BN
If the number parameter is an instance of BN, it returns a BN instance, otherwise a string.
Examples
> caver.utils.convertToPeb('1', 'KLAY')
'1000000000000000000'
> caver.utils.convertToPeb(caver.utils.toBN(1), 'KLAY')
<BN: de0b6b3a7640000>convertFromPeb
caver.utils.convertFromPeb(number [, unit])NOTE: "peb" is the smallest KLAY unit, and you should always use "peb" as the unit of KLAY. Convert to "KLAY" only for display reasons.
Parameters
number
string | number | BN | BigNumber
The value in peb.
unit
string
(optional, defaults to "KLAY") The unit of KLAY to convert your "peb" into. number will be divided by one of the following denominators for the unit provided:
- peb: '1'
- kpeb: '1000'
- Mpeb: '1000000'
- Gpeb: '1000000000'
- Ston: '1000000000'
- uKLAY: '1000000000000'
- mKLAY: '1000000000000000'
- KLAY: '1000000000000000000'
- kKLAY: '1000000000000000000000'
- MKLAY: '1000000000000000000000000'
- GKLAY: '1000000000000000000000000000'
Return Value
string
The string number.
Examples
> caver.utils.convertFromPeb('1', 'KLAY')
'0.000000000000000001'unitMap
caver.utils.unitMapShows all possible KLAY values and their amount in peb.
Return Value
Object
With the following properties:
- peb: '1'
- kpeb: '1000'
- Mpeb: '1000000'
- Gpeb: '1000000000'
- Ston: '1000000000'
- uKLAY: '1000000000000'
- mKLAY: '1000000000000000'
- KLAY: '1000000000000000000'
- kKLAY: '1000000000000000000000'
- MKLAY: '1000000000000000000000000'
- GKLAY: '1000000000000000000000000000'
- TKLAY: '1000000000000000000000000000000'
Examples
> caver.utils.unitMap
{
peb: '1',
kpeb: '1000',
Mpeb: '1000000',
Gpeb: '1000000000',
Ston: '1000000000',
uKLAY: '1000000000000',
mKLAY: '1000000000000000',
KLAY: '1000000000000000000',
kKLAY: '1000000000000000000000',
MKLAY: '1000000000000000000000000',
GKLAY: '1000000000000000000000000000',
TKLAY: '1000000000000000000000000000000'
}klayUnit
caver.utils.klayUnitShows all KLAY units.
Return Value
Object
An object in which the units of KLAY used in Klaytn are defined. Each unit has its name and pebFactor. pebFactor is used when converting KLAY currently translated in each unit to 'peb'.
Examples
> caver.utils.klayUnit
{
peb: { unit: 'peb', pebFactor: 0 },
kpeb: { unit: 'kpeb', pebFactor: 3 },
Mpeb: { unit: 'Mpeb', pebFactor: 6 },
Gpeb: { unit: 'Gpeb', pebFactor: 9 },
ston: { unit: 'ston', pebFactor: 9 },
uKLAY: { unit: 'uKLAY', pebFactor: 12 },
mKLAY: { unit: 'mKLAY', pebFactor: 15 },
KLAY: { unit: 'KLAY', pebFactor: 18 },
kKLAY: { unit: 'kKLAY', pebFactor: 21 },
MKLAY: { unit: 'MKLAY', pebFactor: 24 },
GKLAY: { unit: 'GKLAY', pebFactor: 27 },
TKLAY: { unit: 'TKLAY', pebFactor: 30 }
}padLeft
caver.utils.padLeft(string, characterAmount [, sign])
caver.utils.leftPad(string, characterAmount [, sign]) // ALIASAdds padding on the left of a string. Useful for adding paddings to HEX strings.
Parameters
string
string
The string to add padding on the left.
characterAmount
number
The number of characters the total string should have.
sign
string
(optional) The character sign to use, defaults to 0.
Return Value
string
The padded string.
Examples
> caver.utils.padLeft('0x3456ff', 20)
'0x000000000000003456ff'
> caver.utils.padLeft(0x3456ff, 20)
'0x000000000000003456ff'
> caver.utils.padLeft('Hello', 20, 'x')
'xxxxxxxxxxxxxxxHello'padRight
caver.utils.padRight(str, characterAmount [, sign])
caver.utils.rightPad(str, characterAmount [, sign]) // ALIASAdds padding on the right of a string, Useful for adding paddings to HEX strings.
Parameters
str
string
The string to add padding on the right.
characterAmount
number
The number of characters the total string should have.
sign
string
(optional) The character sign to use, defaults to 0.
Return Value
string
The padded string.
Examples
> caver.utils.padRight('0x3456ff', 20)
'0x3456ff00000000000000'
> caver.utils.padRight(0x3456ff, 20)
'0x3456ff00000000000000'
> caver.utils.padRight('Hello', 20, 'x')
'Helloxxxxxxxxxxxxxxx'trimLeadingZero
caver.utils.trimLeadingZero(hexString)Removes leading zero from 0x-prefixed hex string.
Parameters
hexString
string
A hex string to trim.
Return Value
string
A hex string without leading zero.
Examples
> caver.utils.trimLeadingZero('0x000011')
0x11makeEven
caver.utils.makeEven(hexString)Returns a string to an even length.
Parameters
hexString
string
A hex string to make even.
Return Value
string
A string with even length.
Examples
> caver.utils.makeEven('0x011')
0x0011toTwosComplement
caver.utils.toTwosComplement(num)Converts a negative number into a two's complement.
Parameters
num
number | string | BigNumber
The number to convert.
Return Value
string
The converted hex string.
Examples
> caver.utils.toTwosComplement('-1')
'0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff'
> caver.utils.toTwosComplement(-1)
'0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff'
> caver.utils.toTwosComplement('0x1')
'0x0000000000000000000000000000000000000000000000000000000000000001'
> caver.utils.toTwosComplement(-15)
'0xfffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff1'
> caver.utils.toTwosComplement('-0x1')
'0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff'isContractDeployment
caver.utils.isContractDeployment(transactionObject)Returns true if the given transaction is a smart contract deploy transaction. It returns false if the transaction is not a smart contract deploy transaction. The result is determined by the values of the parameters in the transactionObject. Make sure all the mandatory parameters are set correctly.
Parameters
Return Value
boolean
true means the transaction object is for smart contract deploy.
Examples
> caver.utils.isContractDeployment(caver.transaction.legacyTransaction.create({
to: '0x9957dfd92e4b70f91131c573293343bc5f21f215',
value: caver.utils.toPeb(1, 'KLAY'),
gas: 25000,
}))
false
> caver.utils.isContractDeployment(caver.transaction.legacyTransaction.create({
input: '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',
gas: 200000,
}))
true
> caver.utils.isContractDeployment(caver.transaction.smartContractDeploy.create({
from: '0x88e245dec96830f012f8fc1806bc623b3774560d',
input: '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',
gas: 100000,
}))
true
> caver.utils.isContractDeployment(caver.transaction.feeDelegatedSmartContractDeploy.create({
from: '0x88e245dec96830f012f8fc1806bc623b3774560d',
input: '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',
gas: 100000,
}))
true
> caver.utils.isContractDeployment(caver.transaction.feeDelegatedSmartContractDeployWithRatio.create({
from: '0x88e245dec96830f012f8fc1806bc623b3774560d',
input: '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',
gas: 100000,
feeRatio: 30,
}))
truexyPointFromPublicKey
caver.utils.xyPointFromPublicKey(publicKey)Returns the x and y coordinates of the given publicKey. For more information on key cryptography, see Elliptic-curve cryptography.
NOTE This function does not contain any logic to check whether the public key is valid. The function only split the input publicKey into x and y points by length. To validate public key, please use isValidPublicKey.
Parameters
publicKey
string
The publicKey to get x and y points.
Return Value
Array
An array storing x and y points. Index 0 has x point, and index 1 has y point.
Examples
> caver.utils.xyPointFromPublicKey('0xa5862ded55cd9c7e9ff246dbc264ca5d5c605308f59b74e581b4f089d4c8c88cb9f00df6a56493f6029af215d266c907660ea0f7a4111ea025ea9d9be418fa55')
[
'0xa5862ded55cd9c7e9ff246dbc264ca5d5c605308f59b74e581b4f089d4c8c88c',
'0xb9f00df6a56493f6029af215d266c907660ea0f7a4111ea025ea9d9be418fa55'
]isHexPrefixed
caver.utils.isHexPrefixed(input)Returns true if the input is a 0x-prefixed hex string, otherwise it returns false.
Parameters
input
string
The value to be determined if the parameter is 0x-prefixed hex string or not.
Return Value
boolean
true means the input is 0x-prefixed hex string.
Examples
> caver.utils.isHexPrefixed('0xa5b0cd8c87e77879d64cc064ee239ed6f71cacf9')
true
> caver.utils.isHexPrefixed('0x1')
true
> caver.utils.isHexPrefixed('0xqwer')
false
> caver.utils.isHexPrefixed('1')
falseaddHexPrefix
caver.utils.addHexPrefix(input)Returns a 0x-prefixed hex string. If the input is already 0x-prefixed or a non-hex string, the input value is returned as-is.
Parameters
input
string
string value to be prefixed with 0x.
Return Value
string
0x-prefixed hex string is returned.
Examples
> caver.utils.addHexPrefix('a5b0cd8c87e77879d64cc064ee239ed6f71cacf9')
'0xa5b0cd8c87e77879d64cc064ee239ed6f71cacf9'
> caver.utils.addHexPrefix('0xa5b0cd8c87e77879d64cc064ee239ed6f71cacf9')
'0xa5b0cd8c87e77879d64cc064ee239ed6f71cacf9'stripHexPrefix
caver.utils.stripHexPrefix(input)Returns the result with 0x prefix stripped from input.
NOTE caver.klay.stripHexPrefix is supported from v1.0.1. To use this feature, please install v1.0.1 or higher.
Parameters
input
string
string to remove 0x prefix.
Return Value
string
A string stripped of 0x is returned.
Examples
> caver.utils.stripHexPrefix('a5b0cd8c87e77879d64cc064ee239ed6f71cacf9')
'a5b0cd8c87e77879d64cc064ee239ed6f71cacf9'
> caver.utils.stripHexPrefix('0xa5b0cd8c87e77879d64cc064ee239ed6f71cacf9')
'a5b0cd8c87e77879d64cc064ee239ed6f71cacf9'toBuffer
caver.utils.toBuffer(input)This function converts the input to a Buffer. To convert an object into a Buffer using toBuffer, the object must implement toArray function. For string type input, this function only works with a 0x-prefixed hex string.
Parameters
input
Buffer | string | number | Array | BN | BigNumber | object
The value to be converted to a Buffer.
NOTE BigNumber type is supported since caver-js v1.6.4.
Return Value
Buffer
The value converted to Buffer type is returned.
Examples
// Buffer
> caver.utils.toBuffer(Buffer.alloc(0))
<Buffer >
// 0x-prefixed hex string
> caver.utils.toBuffer('0x1234')
<Buffer 12 34>
// number
> caver.utils.toBuffer(1)
<Buffer 01>
// Array
> caver.utils.toBuffer([1,2,3])
<Buffer 01 02 03>
// BN
> caver.utils.toBuffer(new caver.utils.BN(255))
<Buffer ff>
// Object that implements toArray function
> caver.utils.toBuffer({toArray: function() {return [1,2,3,4]}})
<Buffer 01 02 03 04>
// null or undefined
> caver.utils.toBuffer(null)
<Buffer >
> caver.utils.toBuffer(undefined)
<Buffer >
// non 0x-prefixed hex string
> caver.utils.toBuffer('0xqwer')
Error: Failed to convert string to Buffer. 'toBuffer' function only supports 0x-prefixed hex string
// Object that does not implement toArray function
> caver.utils.toBuffer({})
Error: To convert an object to a buffer, the toArray function must be implemented inside the objectnumberToBuffer
caver.utils.numberToBuffer(input)This function converts a number to a Buffer. The caver.utils.toBuffer has the same behavior as this function when the input is a number.
Parameters
input
string | number | BN | BigNumber
A number to be converted to a Buffer.
Return Value
Buffer
The value converted to Buffer type is returned.
Examples
> caver.utils.numberToBuffer(1)
<Buffer 01>
> caver.utils.numberToBuffer('2')
<Buffer 02>
> caver.utils.numberToBuffer('0x3')
<Buffer 03>
> caver.utils.numberToBuffer(new caver.utils.BN(4))
<Buffer 04>isValidHash
caver.utils.isValidHash(input)Returns true if the input is in 32-bytes hash format, otherwise it returns false.
Parameters
input
string
The value to be examined that if it is in 32-bytes hash format or not.
Return Value
boolean
true means the input is in the format of 32-bytes hash.
Examples
// with '0x' hex prefix
> caver.utils.isValidHash('0xe9a11d9ef95fb437f75d07ce768d43e74f158dd54b106e7d3746ce29d545b550')
true
// without '0x' hex prefix
> caver.utils.isValidHash('e9a11d9ef95fb437f75d07ce768d43e74f158dd54b106e7d3746ce29d545b550')
true
> caver.utils.isValidHash('0x1')
falseisValidHashStrict
caver.utils.isValidHashStrict(input)Returns true if the input is in 0x-prefixed 32-bytes hash format, otherwise it returns false. This function only looks at the input and determines if it is in the format of 0x-prefixed 32-bytes hash. Difference to caver.utils.isValidHash is that it expects HEX to be prefixed with 0x.
Parameters
input
string
The value to be examined that if it is in the format of 0x-prefixed 32-bytes hash or not.
Return Value
boolean
true means the input is in the format of 0x-prefixed 32-bytes hash.
Examples
// with '0x' hex prefix
> caver.utils.isValidHashStrict('0xe9a11d9ef95fb437f75d07ce768d43e74f158dd54b106e7d3746ce29d545b550')
true
// without '0x' hex prefix
> caver.utils.isValidHashStrict('e9a11d9ef95fb437f75d07ce768d43e74f158dd54b106e7d3746ce29d545b550')
false
> caver.utils.isValidHashStrict('0x1')
falseisTxHash
caver.utils.isTxHash(input)Returns true if the input is in transaction hash format, otherwise it returns false. This function only looks at the input and determines if it is in the format of a transaction hash.
NOTE This function has been deprecated. Use isValidHash to determine if a valid hash is 32 bytes long.
Parameters
input
string
The value to be determined if the parameter is in the format of transaction hash or not.
Return Value
boolean
true means the input is in the format of transaction hash.
Examples
// with '0x' hex prefix
> caver.utils.isTxHash('0xe9a11d9ef95fb437f75d07ce768d43e74f158dd54b106e7d3746ce29d545b550')
true
// without '0x' hex prefix
> caver.utils.isTxHash('e9a11d9ef95fb437f75d07ce768d43e74f158dd54b106e7d3746ce29d545b550')
true
> caver.utils.isTxHash('0x1')
falseisTxHashStrict
caver.utils.isTxHashStrict(input)Returns true if the input is in transaction hash format, otherwise it returns false. This function only looks at the input and determines if it is in the format of a transaction hash. Difference to caver.utils.isTxHash is that it expects HEX to be prefixed with 0x.
NOTE This function has been deprecated. Use isValidHashStrict to determine if a valid hash is 32 bytes long.
Parameters
input
string
The value to be determined if the parameter is in the format of transaction hash or not.
Return Value
boolean
true means the input is in the format of transaction hash.
Examples
// with '0x' hex prefix
> caver.utils.isTxHashStrict('0xe9a11d9ef95fb437f75d07ce768d43e74f158dd54b106e7d3746ce29d545b550')
true
// without '0x' hex prefix
> caver.utils.isTxHashStrict('e9a11d9ef95fb437f75d07ce768d43e74f158dd54b106e7d3746ce29d545b550')
false
> caver.utils.isTxHashStrict('0x1')
falseisValidPrivateKey
caver.utils.isValidPrivateKey(privateKey)Returns true if privateKey is valid, otherwise it returns false.
Parameters
privateKey
string
A private key string to validate.
Return Value
boolean
true means the privateKey is valid.
Examples
> caver.utils.isValidPrivateKey('0x{private key}')
true
> caver.utils.isValidPrivateKey('{private key}')
true
> caver.utils.isValidPrivateKey('a5b0cd8c87e77879d64cc064ee239ed6f71cacf9')
falseisValidPublicKey
caver.utils.isValidPublicKey(publicKey)Returns true if publicKey is valid, otherwise it returns false.
Parameters
publicKey
string
A public key string to validate.
Return Value
boolean
true means the publicKey is valid.
Examples
// validation with uncompressed public key
> caver.utils.isValidPublicKey('0xbd6405a7f14f57ecea4a6ffe774ee26d051f7eed13257c9a574055b20e42bab0e8beba92e2e675101eb2a55ba4693080d0bf14548beae7bc93b18b72d10dd350')
true
// validation with compressed public key
> caver.utils.isValidPublicKey('0x02bd6405a7f14f57ecea4a6ffe774ee26d051f7eed13257c9a574055b20e42bab0')
true
> caver.utils.isValidPublicKey('{private key}')
false
> caver.utils.isValidPublicKey('0x{private key}')
false
> caver.utils.isValidPublicKey('a5b0cd8c87e77879d64cc064ee239ed6f71cacf9')
falseisValidRole
caver.utils.isValidRole(role)Returns true if a role is valid, otherwise it returns false. You can check roles supported by caver-js through caver.wallet.keyring.role.
Parameters
role
string
A role string to validate.
Return Value
boolean
true means the role is valid.
Examples
> caver.utils.isValidRole('roleTransactionKey')
true
> caver.utils.isValidRole('role')
falseisValidBlockNumberCandidate
caver.utils.isValidBlockNumberCandidate(input)Validates the block number (or block tag string).
The block number should be one of the types below:
predefined block number ex:) 'latest', 'earliest', 'pending', 'genesis'
hex
finite number
Parameters
blockNumber
string | number
The block number to validate. This can be block number in number type or block tag(latest, pending, earliest, genesis) string.
Return Value
boolean
true means blockNumber is valid.
Examples
> caver.utils.isValidBlockNumberCandidate('latest')
true
> caver.utils.isValidBlockNumberCandidate('0x1')
true
> caver.utils.isValidBlockNumberCandidate(1)
trueisPredefinedBlockNumber
caver.utils.isPredefinedBlockNumber(input)Returns true if the parameter is predefined block tag.
Parameters
predefinedBlock
string
The predefined block.
Return Value
boolean
true means predefinedBlock is valid predefined block tag.
Examples
> caver.utils.isPredefinedBlockNumber('latest')
true
> caver.utils.isPredefinedBlockNumber('0x1')
falseisEmptySig
caver.utils.isEmptySig(sig)Returns true if sig is in the format of empty signature (SignatureData { _v: '0x01', _r: '0x', _s: '0x' } or [SignatureData { _v: '0x01', _r: '0x', _s: '0x' }]), otherwise it returns false.
In caver-js, if signatures or feePayerSignatures is empty, the value representing an empty signature, [SignatureData { _v: '0x01', _r: '0x', _s: '0x' }], is returned for the property. This function is used to check whether the given signature is [SignatureData { _v: '0x01', _r: '0x', _s: '0x' }] (or SignatureData { _v: '0x01', _r: '0x', _s: '0x' } in the 'LEGACY' transaction).
Parameters
Return Value
boolean
true means the sig is empty.
Examples
> caver.utils.isEmptySig(caver.wallet.keyring.signatureData.emtpySig)
true
> caver.utils.isEmptySig([caver.wallet.keyring.signatureData.emtpySig])
trueisKlaytnWalletKey
caver.utils.isKlaytnWalletKey(key)Returns true if key is in KlaytnWalletKey format, otherwise it returns false.
Parameters
key
string
A key string to check in the format of KlaytnWalletKey or not.
Return Value
boolean
true means the key is 0x{private key}0x{type}0x{address in hex} or {private key}0x{type}0x{address in hex}.
Examples
> caver.utils.isKlaytnWalletKey('0x{private key}0x{type}0x{address in hex}')
true
> caver.utils.isKlaytnWalletKey('{private key}0x{type}0x{address in hex}')
true
> caver.utils.isKlaytnWalletKey('0x{private key}')
falsebufferToHex
caver.utils.bufferToHex(buffer)Converts buffer to 0x-prefixed hex string.
Parameters
buffer
Buffer
A buffer to convert to hex string.
Return Value
string
The 0x-prefixed hex string.
Examples
> caver.utils.bufferToHex(Buffer.from('5b9ac8', 'hex'))
'0x5b9ac8'
> caver.utils.bufferToHex(Buffer.alloc(0))
'0x'parseKlaytnWalletKey
caver.utils.parseKlaytnWalletKey(key)Parses KlaytnWalletKey string to an array which includes "private key", "type", "address".
Parameters
Return Value
Array
The parsed KlaytnWalletKey.
Examples
> caver.utils.parseKlaytnWalletKey('0x{private key}0x{type}0x{address in hex}')
[
'0x{private key}',
'0x00',
'0x885ebdb17c221ef695936b18a0263d6399e14d60'
]hashMessage
caver.utils.hashMessage(message)Hashes message with Klaytn specific prefix: keccak256("\x19Klaytn Signed Message:\n" + len(message) + message))
Parameters
message
string
A message to hash. If it is a HEX string, it will be UTF-8 decoded first.
Return Value
string
The hashed message with Klaytn specific prefix.
Examples
> caver.utils.hashMessage('Hello')
'0x640bfab59b6e27468abd367888f4ab1a1c77aa2b45e76a1d3adcbd039c305917'recover
caver.utils.recover(message, signature [, isHashed])Recovers the Klaytn address that was used to sign the given data.
Parameters
message
string
Either message or hashed message.
isHashed
boolean
(optional, default: false) If the last parameter is true, the given message will NOT automatically be prefixed with "\x19Klaytn Signed Message:\n" + message.length + message, and will be assumed to be already prefixed.
Return Value
string
The Klaytn address used to sign this data.
Examples
> caver.utils.recover('message', new caver.wallet.keyring.signatureData(['0x1b', '0x50a80...', '0x021de...']))
'0xe8b3a6ef12f9506e1df9fd445f9bb4488a482122'
> caver.utils.recover('message', ['0x1b', '0x50a80...', '0x021de...'])
'0xe8b3a6ef12f9506e1df9fd445f9bb4488a482122'
> caver.utils.recover('message', { v: '0x1b', r: '0x50a80...', s: '0x021de...' })
'0xe8b3a6ef12f9506e1df9fd445f9bb4488a482122'
> caver.utils.recover('0xe960248437f2134a77a9aa0ebcbb6523aec095f23b02e25f16fd95e99b099daa', sig, true)
'0xe8b3a6ef12f9506e1df9fd445f9bb4488a482122'recoverPublicKey
caver.utils.recoverPublicKey(message, signature [, isHashed])Recovers the public key that was used to sign the given data.
NOTE caver.utils.recoverPublicKey is supported since caver-js v1.6.3.
Parameters
message
string
Either message or hashed message.
isHashed
boolean
(optional, default: false) Whether the message passed as a parameter is hashed with the prefix "\x19Klaytn Signed Message:\n" + message.length + message.
Return Value
string
The public key used to sign this data.
Examples
> caver.utils.recoverPublicKey('Some Message', new caver.wallet.keyring.signatureData([
'0x1b',
'0x8213e560e7bbe1f2e28fd69cbbb41c9108b84c98cd7c2c88d3c8e3549fd6ab10',
'0x3ca40c9e20c1525348d734a6724db152b9244bff6e0ff0c2b811d61d8f874f00',
]))
'0xb5df4d5e6b4ee7a136460b911a69030fdd42c18ed067bcc2e25eda1b851314fad994c5fe946aad01ca2e348d4ff3094960661a8bc095f358538af54aeea48ff3'
> caver.utils.recoverPublicKey('Some Message', [
'0x1b',
'0x8213e560e7bbe1f2e28fd69cbbb41c9108b84c98cd7c2c88d3c8e3549fd6ab10',
'0x3ca40c9e20c1525348d734a6724db152b9244bff6e0ff0c2b811d61d8f874f00',
])
'0xb5df4d5e6b4ee7a136460b911a69030fdd42c18ed067bcc2e25eda1b851314fad994c5fe946aad01ca2e348d4ff3094960661a8bc095f358538af54aeea48ff3'
> caver.utils.recoverPublicKey('0x8ed2036502ed7f485b81feaec1c581d236a8b711e55a24077724879c8a263c2a', {
v: '0x1b',
r: '0x3acab5ba6f884eccfb9642018aa6debab1310d99b7a84ae9acb8f52f567cf16a',
s: '0x3501ae03809bf93222c4683642fa8fdc36385709c70ed8e7b883b34d66a5b8a4',
}, true)
'0xdd352dbe1c49aa9addaa3ca762de476a1b4deca3ac15fbb7fac153737b3ddb1e3249e1c2d86d5cbeaf6d30d366a211532683b59cb5f402bf3fe14989a378d45d'publicKeyToAddress
caver.utils.publicKeyToAddress('0x{public key}')Returns an address derived from a public key. This function simply converts the public key string into an address form by hashing it. It has nothing to do with an actual account on Klaytn.
NOTE caver.utils.publicKeyToAddress is supported since caver-js v1.6.3.
Parameters
publicKey
string
The public key string to get the address.
Return Value
string
The address string derived from a public key.
Examples
> caver.utils.publicKeyToAddress('0xb5df4d5e6b4ee7a136460b911a69030fdd42c18ed067bcc2e25eda1b851314fad994c5fe946aad01ca2e348d4ff3094960661a8bc095f358538af54aeea48ff3')
'0xA84A1CE657e9d5b383cECE6f4bA365e23Fa234Dd'compressPublicKey
caver.utils.compressPublicKey(uncompressedPublicKey)Compresses the uncompressed public key.
Parameters
uncompressedPublicKey
string
An uncompressed public key.
Return Value
string
A compressed public key.
Examples
> caver.utils.compressPublicKey('0x62cef87819b82f62e9c0a38c1fa7dfa089084959df86aca19ff2f6c903db2248b45dc23220ee6bcd8753bb9df8ce7d58e56eabebb14479f3a0ca5ccd4bdea632')
'0x0262cef87819b82f62e9c0a38c1fa7dfa089084959df86aca19ff2f6c903db2248'decompressPublicKey
caver.utils.decompressPublicKey(compressedPublicKey)Decompresses the compressed public key.
Parameters
compressedPublicKey
string
A compressed public key.
Return Value
string
An uncompressed public key.
Examples
> caver.utils.decompressPublicKey('0x0262cef87819b82f62e9c0a38c1fa7dfa089084959df86aca19ff2f6c903db2248')
'0x62cef87819b82f62e9c0a38c1fa7dfa089084959df86aca19ff2f6c903db2248b45dc23220ee6bcd8753bb9df8ce7d58e56eabebb14479f3a0ca5ccd4bdea632'isCompressedPublicKey
caver.utils.isCompressedPublicKey(publicKey)Returns true if public key is compressed, otherwise false.
Parameters
publicKey
string
A public key.
Return Value
boolean
true means compressed.
Examples
> caver.utils.isCompressedPublicKey('0x0262cef87819b82f62e9c0a38c1fa7dfa089084959df86aca19ff2f6c903db2248')
truedecodeSignature
caver.utils.decodeSignature('0x{signature}')Decodes a raw signature data composed of 'R(32 byte) + S(32 byte) + V(1byte)'.
NOTE caver.utils.decodeSignature is supported since caver-js v1.6.3.
Parameters
signature
string
The signature string to decode. It is composed of R(32bytes) + S(32bytes) + V(1byte).
Return Value
object
A SignatureData instance that includes v, r and s.
Examples
> caver.utils.decodeSignature('0xc69018da9396c4b87947e0784625af7475caf46e2af9cf57a44673ff0f625258642d8993751ae67271bcc131aa065adccf9f16fc4953f9c48f4a80d675c09ae81b')
SignatureData {
_v: '0x1b',
_r: '0xc69018da9396c4b87947e0784625af7475caf46e2af9cf57a44673ff0f625258',
_s: '0x642d8993751ae67271bcc131aa065adccf9f16fc4953f9c48f4a80d675c09ae8'
}Last updated