caver.utils (~v1.4.1)
caver-js utility APIs.
caver.utils provides utility functions.
randomHex
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 preficed with "0x".
Return Value
String
The generated random HEX string.
Example
_
The underscore library for many convenience JavaScript functions.
See the underscore API reference for details.
Example
BN
The BN.js library for calculating with big numbers in JavaScript. See the BN.js documentation for details.
Parameters
mixed
String | Number
A number, number string or HEX string to convert to a BN object.
Return Value
Object
Example
isBN
Checks if a given value is a BN.js instance.
Parameters
bn
Object
Return Value
Boolean
Example
isBigNumber
Checks if a given value is a BigNumber.js instance.
Parameters
bignumber
Object
Return Value
Boolean
true if a given value is a BigNumber.js instance.
Example
sha3
Calculates the sha3 of the input.
NOTE: To mimic the sha3 behavior of Solidity use caver.utils.soliditySha3.
Parameters
string
String
A string to hash.
Return Value
String
The result hash.
Example
soliditySha3
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
isHex
Checks if a given string is a HEX string.
Parameters
hex
String | HEX
The given HEX string.
Return Value
Boolean
true if a given string is a HEX string.
Example
isHexStrict
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 | HEX
The given HEX string.
Return Value
Boolean
true if a given string is a HEX string.
Example
isAddress
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
toChecksumAddress
Converts an upper or lowercase Klaytn address to a checksum address.
Parameters
address
String
An address string.
Return Value
String
The checksum address.
Examples
checkAddressChecksum
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
toHex
Converts any given value to HEX. Number strings will 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
toBN
Safely converts any given value (including BigNumber.js instances) into a BN.js instance, for handling big numbers in JavaScript.
NOTE: For just the BN.js class, use caver.utils.BN.
Parameters
number
String | Number | HEX
Number to convert to a big number.
Return Value
Object
Examples
hexToNumberString
Returns the number representation of a given HEX value as a string.
Parameters
hexString
HEX String
A HEX string to be converted.
Return Value
String
The number as a string.
Examples
hexToNumber
Returns the number representation of a given HEX value.
NOTE: This is not useful for big numbers, rather use caver.utils.toBN.
Parameters
hexString
HEX String
A HEX string to be converted.
Return Value
Number
The number representation of a given HEX value.
Examples
numberToHex
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
hexToUtf8
Returns 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
hexToAscii
Returns the ASCII string representation of a given HEX value.
Parameters
hex
String
A HEX string to convert to a ASCII string.
Return Value
String
The ASCII string.
Examples
utf8ToHex
Returns the HEX representation of a given UTF-8 string.
Parameters
string
String
A UTF-8 string to convert to a HEX string.
Return Value
String
The HEX string.
Examples
asciiToHex
Returns the HEX representation of a given ASCII string.
Parameters
string
String
An ASCII string to convert to a HEX string.
Return Value
String
The HEX string.
Examples
hexToBytes
Returns a byte array from the given HEX string.
Parameters
hex
HEX String
A HEX string to be converted.
Return Value
Array
The byte array.
Examples
bytesToHex
Returns a HEX string from a byte array.
Parameters
byteArray
Array
A byte array to convert.
Return Value
String
The HEX string.
Examples
toPeb
Converts any KLAY value into peb.
NOTE: "peb" is the smallest KLAY unit, and you should always make calculations in peb and convert only for display reasons.
Parameters
number
String | Number | BN
The value.
unit
String
(optional, defaults to "KLAY") KLAY to convert from. Possible units are:
- 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
Examples
fromPeb
NOTE: "peb" is the smallest KLAY unit, and you should always make calculations in KLAY and convert only for display reasons.
Parameters
number
String | Number | BN
The value in peb.
unit
String
(optional, defaults to "KLAY") KLAY to convert to. Possible units are:
- 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
Examples
unitMap
Shows 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'
Examples
padLeft
Adds a 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
padRight
Adds a padding on the right of a string, Useful for adding paddings to HEX strings.
Parameters
string
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
toTwosComplement
Converts a negative number into a two's complement.
Parameters
number
Number | String | BigNumber
The number to convert.
Return Value
String
The converted hex string.
Examples
isContractDeployment
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.
NOTE caver.klay.isContractDeployment is supported from v1.0.1-rc.8. To use this feature, please install v1.0.1-rc.8 or higher.
Parameters
transactionObject
Object
Transaction object that you want to determine if the transaction is for smart contract deploy.
Return Value
Boolean
true means the transaction object is for smart contract deploy.
Examples
xyPointFromPublicKey
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.
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
isHexPrefixed
Returns true if input is a 0x-prefixed hex string, otherwise it returns false.
NOTE caver.klay.isHexPrefixed is supported from v1.0.1. To use this feature, please install v1.0.1 or higher.
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
addHexPrefix
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.
NOTE caver.klay.addHexPrefix is supported from v1.0.1. To use this feature, please install v1.0.1 or higher.
Parameters
input
String
String value to be prefixed with 0x.
Return Value
String
0x-prefixed hex string is returned.
Examples
stripHexPrefix
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
toBuffer
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.
NOTE caver.klay.toBuffer is supported from v1.1.0. To use this feature, please install v1.1.0 or higher.
Parameters
input
Buffer | String | Number | Array | BN | Object
The value to be converted to a Buffer.
Return Value
Buffer
The value converted to Buffer type is returned.
Examples
numberToBuffer
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.
NOTE caver.klay.numberToBuffer is supported from v1.1.0. To use this feature, please install v1.1.0 or higher.
Parameters
input
String | Number | BN
A number to be converted to a Buffer.
Return Value
Type
Description
---
---
Buffer
The value converted to Buffer type is returned.
Examples
```javascript
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>
Returns true if 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 caver.klay.isTxHash is supported from v1.2.0-rc.1. To use this feature, please install v1.2.0-rc.1 or higher. Parameters
input
String
The value to be determined if the parameter is in the format of transaction hash or not.
Return Value
Type
Description
---
---
Boolean
true means the input is in format of transaction hash.
Examples
```javascript
// with '0x' hex prefix
caver.utils.isTxHash('0xe9a11d9ef95fb437f75d07ce768d43e74f158dd54b106e7d3746ce29d545b550') true // without '0x' hex prefix caver.utils.isTxHash('e9a11d9ef95fb437f75d07ce768d43e74f158dd54b106e7d3746ce29d545b550') true caver.utils.isTxHash('0x1') false
Returns true if 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 caver.klay.isTxHashStrict is supported from v1.2.0-rc.1. To use this feature, please install v1.2.0-rc.1 or higher. Parameters
input
String
The value to be determined if the parameter is in the format of transaction hash or not.
Return Value
Type
Description
---
---
Boolean
true means the input is in the format of transaction hash.
Examples
```javascript
// with '0x' hex prefix
caver.utils.isTxHashStrict('0xe9a11d9ef95fb437f75d07ce768d43e74f158dd54b106e7d3746ce29d545b550') true // without '0x' hex prefix caver.utils.isTxHashStrict('e9a11d9ef95fb437f75d07ce768d43e74f158dd54b106e7d3746ce29d545b550') false caver.utils.isTxHashStrict('0x1') false
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
isValidPublicKey
Returns true if publicKey is valid, otherwise it returns false.
NOTE caver.utils.isValidPublicKey is supported since caver-js v1.2.0.
Parameters
publicKey
String
A public key string to validate.
Return Value
Boolean
true means the publicKey is valid.
Examples
isValidRole
Returns true if role is valid, otherwise it returns false. Roles that are currently defined for AccountKeyRoleBased are transactionKey, updateKey, and feePayerKey.
NOTE caver.utils.isValidRole is supported since caver-js v1.2.0.
Parameters
role
String
A role string to validate.
Return Value
Boolean
true means the role is valid.
Examples
isEmptySig
Returns true if sig is in the format of empty signature ([['0x01', '0x', '0x']] or ['0x01', '0x', '0x']), otherwise it returns false.
When RLP-encoding a transaction in caver-js, if signatures or feePayerSignatures is empty, the value representing an empty signature, [['0x01', '0x', '0x']], is returned for the property. This function is used to check whether the given signature is [['0x01', '0x', '0x']] (or ['0x01', '0x', '0x'] in the 'LEGACY' transaction).
NOTE caver.utils.isEmptySig is supported since caver-js v1.2.0.
Parameters
sig
Array
An array of signatures to check empty or not.
Return Value
Boolean
true means the sig is [['0x01', '0x', '0x']] or ['0x01', '0x', '0x'].
Examples
isKlaytnWalletKey
Returns true if key is in KlaytnWalletKey format, otherwise it returns false.
NOTE caver.utils.isKlaytnWalletKey has been updated with the additional logic for a more accurate result since caver-js v1.3.2-rc.3.
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
bufferToHex
Converts buffer to 0x-prefixed hex string.
NOTE caver.utils.bufferToHex is supported since caver-js v1.3.2-rc.1.
Parameters
buffer
Buffer
A buffer to convert to hex string.
Return Value
String
The 0x-prefixed hex string.
Examples
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