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

NameTypeDescription

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

TypeDescription

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

NameTypeDescription

number

string | number

number to convert to a big number.

Return Value

TypeDescription

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

NameTypeDescription

bn

object

A BN.js instance.

Return Value

TypeDescription

boolean

true if a given value is a BN.js instance.

Example

> var number = new caver.utils.BN(10)
> caver.utils.isBN(number)
true

isBigNumber

caver.utils.isBigNumber(bignumber)

Checks if a given value is a BigNumber.js instance.

Parameters

NameTypeDescription

bignumber

object

A BigNumber.js instance.

Return Value

TypeDescription

boolean

true if a given value is a BigNumber.js instance.

Example

> var number = new caver.utils.BigNumber(10)
> caver.utils.isBigNumber(number)
true

sha3

caver.utils.sha3(str)
caver.utils.keccak256(str) // ALIAS

Calculates the sha3 of the input.

NOTE: To mimic the sha3 behavior of Solidity use caver.utils.soliditySha3.

Parameters

NameTypeDescription

str

string

A string to hash.

Return Value

TypeDescription

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

NameTypeDescription

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

TypeDescription

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

NameTypeDescription

hex

string

The given HEX string.

Return Value

TypeDescription

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')
false

isHexStrict

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

NameTypeDescription

hex

string

The given HEX string.

Return Value

TypeDescription

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')
false

isAddress

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

NameTypeDescription

address

string

An address string.

Return Value

TypeDescription

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 checksum

toChecksumAddress

caver.utils.toChecksumAddress(address)

Converts an upper or lowercase Klaytn address to a checksum address.

Parameters

NameTypeDescription

address

string

An address string.

Return Value

TypeDescription

string

The checksum address.

Examples

> caver.utils.toChecksumAddress('0xc1912fee45d61c87cc5ea59dae31190fffff232d')
'0xc1912fEE45d61C87Cc5EA59DaE31190FFFFf232d'

> caver.utils.toChecksumAddress('0XC1912FEE45D61C87CC5EA59DAE31190FFFFF232D')
'0xc1912fEE45d61C87Cc5EA59DaE31190FFFFf232d' // same as above

checkAddressChecksum

caver.utils.checkAddressChecksum(address)

Checks the checksum of a given address. Will also return false on non-checksum addresses.

Parameters

NameTypeDescription

address

string

An address string.

Return Value

TypeDescription

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')
true

toHex

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

NameTypeDescription

mixed

string | number | BN | BigNumber

The input to convert to HEX.

Return Value

TypeDescription

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

NameTypeDescription

hexstring

string

A HEX string to be converted.

Return Value

TypeDescription

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

NameTypeDescription

hexstring

string

A HEX string to be converted.

Return Value

TypeDescription

number

The number representation of a given HEX value.

Examples

> caver.utils.hexToNumber('0xea')
234

numberToHex

caver.utils.numberToHex(number)

Returns the HEX representation of a given number value.

Parameters

NameTypeDescription

number

string | number | BN | BigNumber

A number as string or number.

Return Value

TypeDescription

string

The HEX value of the given number.

Examples

> caver.utils.numberToHex('234')
'0xea'

hexToUtf8

caver.utils.hexToUtf8(hex)
caver.utils.hexToString(hex) // ALIAS

Returns the UTF-8 string representation of a given HEX value.

Parameters

NameTypeDescription

hex

string

A HEX string to convert to a UTF-8 string.

Return Value

TypeDescription

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

NameTypeDescription

hex

string

A HEX string to convert to an ASCII string.

Return Value

TypeDescription

string

The ASCII string.

Examples

> caver.utils.hexToAscii('0x4920686176652031303021')
'I have 100!'

utf8ToHex

caver.utils.utf8ToHex(str)
caver.utils.stringToHex(str) // ALIAS

Returns the HEX representation of a given UTF-8 string.

Parameters

NameTypeDescription

str

string

A UTF-8 string to convert to a HEX string.

Return Value

TypeDescription

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

NameTypeDescription

str

string

An ASCII string to convert to a HEX string.

Return Value

TypeDescription

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

NameTypeDescription

hex

string

A HEX string to be converted.

Return Value

TypeDescription

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

NameTypeDescription

byteArray

Array

A byte array to convert.

Return Value

TypeDescription

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

NameTypeDescription

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

TypeDescription

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

NameTypeDescription

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

TypeDescription

string

The string number.

Examples

> caver.utils.convertFromPeb('1', 'KLAY')
'0.000000000000000001'

unitMap

caver.utils.unitMap

Shows all possible KLAY values and their amount in peb.

Return Value

TypeDescription

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.klayUnit

Shows all KLAY units.

Return Value

TypeDescription

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]) // ALIAS

Adds padding on the left of a string. Useful for adding paddings to HEX strings.

Parameters

NameTypeDescription

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

TypeDescription

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]) // ALIAS

Adds padding on the right of a string, Useful for adding paddings to HEX strings.

Parameters

NameTypeDescription

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

TypeDescription

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

NameTypeDescription

hexString

string

A hex string to trim.

Return Value

TypeDescription

string

A hex string without leading zero.

Examples

> caver.utils.trimLeadingZero('0x000011')
0x11

makeEven

caver.utils.makeEven(hexString)

Returns a string to an even length.

Parameters

NameTypeDescription

hexString

string

A hex string to make even.

Return Value

TypeDescription

string

A string with even length.

Examples

> caver.utils.makeEven('0x011')
0x0011

toTwosComplement

caver.utils.toTwosComplement(num)

Converts a negative number into a two's complement.

Parameters

NameTypeDescription

num

number | string | BigNumber

The number to convert.

Return Value

TypeDescription

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

NameTypeDescription

transactionObject

object

An instance of Transaction to check contract deploy transaction or not.

Return Value

TypeDescription

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,
}))
true

xyPointFromPublicKey

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

NameTypeDescription

publicKey

string

The publicKey to get x and y points.

Return Value

TypeDescription

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

NameTypeDescription

input

string

The value to be determined if the parameter is 0x-prefixed hex string or not.

Return Value

TypeDescription

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')
false

addHexPrefix

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

NameTypeDescription

input

string

string value to be prefixed with 0x.

Return Value

TypeDescription

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

NameTypeDescription

input

string

string to remove 0x prefix.

Return Value

TypeDescription

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

NameTypeDescription

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

TypeDescription

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 object

numberToBuffer

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

NameTypeDescription

input

string | number | BN | BigNumber

A number to be converted to a Buffer.

Return Value

TypeDescription

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