caver.utils
provides utility functions.
caver.utils.randomHex(size)
The randomHex library to generate cryptographically strong pseudo-random HEX strings from a given byte size.
Parameters
Name | Type | Description |
size | number | The byte size for the HEX string, e.g., |
Return Value
Type | Description |
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){ ... })...
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
Name | Type | Description |
number | string | number | number to convert to a big number. |
Return Value
Type | Description |
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'
caver.utils.isBN(bn)
Checks if a given value is a BN.js instance.
Parameters
Name | Type | Description |
bn | object | A BN.js instance. |
Return Value
Type | Description |
boolean |
|
Example
> var number = new BN(10)> caver.utils.isBN(number)true
caver.utils.isBigNumber(bignumber)
Checks if a given value is a Bignumber.js instance.
Parameters
Name | Type | Description |
bignumber | object | A Bignumber.js instance. |
Return Value
Type | Description |
boolean |
|
Example
> var number = new Bignumber(10)> caver.utils.isBigNumber(number)true
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
Name | Type | Description |
str | string | A string to hash. |
Return Value
Type | Description |
string | The result hash. |
Example
> caver.utils.sha3('234') // taken as string'0xc1912fee45d61c87cc5ea59dae311904cd86b84fee17cc96966216f811ce6a79'> caver.utils.sha3(new 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 numbernull> caver.utils.sha3('0xea') // will be converted to a byte array first, and then hashed'0x2f20677459120677484f7104c76deb6846a2c071f9b3152c103bb12cd54d1a4a'
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
Name | Type | Description | | | | | |
paramX | Mixed | Any type, or an object with | number | BN | HEX | number | BN |
Return Value
Type | Description |
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 BN('234')) // same as above'0x61c831beab28d67d1bb40b5ae1a11e2757fa842f031a2d0bc94a7867bc5d26c2'> caver.utils.soliditySha3({type: 'uint256', value: '234'})) // same as above'0x61c831beab28d67d1bb40b5ae1a11e2757fa842f031a2d0bc94a7867bc5d26c2'> caver.utils.soliditySha3({t: 'uint', v: new 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'
caver.utils.isHex(hex)
Checks if a given string is a HEX string.
Parameters
Name | Type | Description |
hex | string | The given HEX string. |
Return Value
Type | Description |
boolean |
|
Example
> caver.utils.isHex('0xc1912')true> caver.utils.isHex('c1912')true> caver.utils.isHex('0xZ1912')false> caver.utils.isHex('Hello')false
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
Name | Type | Description |
hex | string | The given HEX string. |
Return Value
Type | Description |
boolean |
|
Example
> caver.utils.isHexStrict('0xc1912')true> caver.utils.isHexStrict('c1912')false> caver.utils.isHexStrict('0xZ1912')false> caver.utils.isHex('Hello')false
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
Name | Type | Description |
address | string | An address string. |
Return Value
Type | Description |
boolean |
|
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
caver.utils.toChecksumAddress(address)
Converts an upper or lowercase Klaytn address to a checksum address.
Parameters
Name | Type | Description |
address | string | An address string. |
Return Value
Type | Description |
string | The checksum address. |
Examples
> caver.utils.toChecksumAddress('0xc1912fee45d61c87cc5ea59dae31190fffff232d')'0xc1912fEE45d61C87Cc5EA59DaE31190FFFFf232d'> caver.utils.toChecksumAddress('0XC1912FEE45D61C87CC5EA59DAE31190FFFFF232D')'0xc1912fEE45d61C87Cc5EA59DaE31190FFFFf232d' // same as above
caver.utils.checkAddressChecksum(address)
Checks the checksum of a given address. Will also return false
on non-checksum addresses.
Parameters
Name | Type | Description |
address | string | An address string. |
Return Value
Type | Description |
boolean |
|
Examples
> caver.utils.checkAddressChecksum('0xc1912fEE45d61C87Cc5EA59DaE31190FFFFf232d')true
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
Name | Type | Description |
mixed | string | number | BN | Bignumber | The input to convert to HEX. |
Return Value
Type | Description |
string | The resulting HEX string. |
Examples
> caver.utils.toHex('234')'0xea'> caver.utils.toHex(234)'0xea'> caver.utils.toHex(new BN('234'))'0xea'> caver.utils.toHex(new Bignumber('234'))'0xea'> caver.utils.toHex('I have 100€')'0x49206861766520313030e282ac'
caver.utils.hexToNumberString(hex)
Returns the number representation of a given HEX value as a string.
Parameters
Name | Type | Description |
hexstring | string | A HEX string to be converted. |
Return Value
Type | Description |
string | The number as a string. |
Examples
> caver.utils.hexToNumberString('0xea')"234"
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
Name | Type | Description |
hexstring | string | A HEX string to be converted. |
Return Value
Type | Description |
number | The number representation of a given HEX value. |
Examples
> caver.utils.hexToNumber('0xea')234
caver.utils.numberToHex(number)
Returns the HEX representation of a given number value.
Parameters
Name | Type | Description |
number | string | number | BN | Bignumber | A number as string or number. |
Return Value
Type | Description |
string | The HEX value of the given number. |
Examples
> caver.utils.numberToHex('234')'0xea'
caver.utils.hexToUtf8(hex)caver.utils.hexToString(hex) // ALIAS
Returns the UTF-8 string representation of a given HEX value.
Parameters
Name | Type | Description |
hex | string | A HEX string to convert to a UTF-8 string. |
Return Value
Type | Description |
string | The UTF-8 string. |
Examples
> caver.utils.hexToUtf8('0x49206861766520313030e282ac')'I have 100€'
caver.utils.hexToAscii(hex)
Returns the ASCII string representation of a given HEX value.
Parameters
Name | Type | Description |
hex | string | A HEX string to convert to an ASCII string. |
Return Value
Type | Description |
string | The ASCII string. |
Examples
> caver.utils.hexToAscii('0x4920686176652031303021')'I have 100!'
caver.utils.utf8ToHex(str)caver.utils.stringToHex(str) // ALIAS
Returns the HEX representation of a given UTF-8 string.
Parameters
Name | Type | Description |
str | string | A UTF-8 string to convert to a HEX string. |
Return Value
Type | Description |
string | The HEX string. |
Examples
> caver.utils.utf8ToHex('I have 100€')'0x49206861766520313030e282ac'
caver.utils.asciiToHex(str)
Returns the HEX representation of a given ASCII string.
Parameters
Name | Type | Description |
str | string | An ASCII string to convert to a HEX string. |
Return Value
Type | Description |
string | The HEX string. |
Examples
> caver.utils.asciiToHex('I have 100!')'0x4920686176652031303021'
caver.utils.hexToBytes(hex)
Returns a byte array from the given HEX string.
Parameters
Name | Type | Description |
hex | string | A HEX string to be converted. |
Return Value
Type | Description |
Array | The byte array. |
Examples
> caver.utils.hexToBytes('0x000000ea')[ 0, 0, 0, 234 ]
caver.utils.bytesToHex(byteArray)
Returns a HEX string from a byte array.
Parameters
Name | Type | Description |
byteArray | Array | A byte array to convert. |
Return Value
Type | Description |
string | The HEX string. |
Examples
> caver.utils.bytesToHex([ 72, 101, 108, 108, 111, 33, 36 ])'0x48656c6c6f2124'
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
Name | Type | Description |
number | string | number | BN | The value. |
unit | string | (optional, defaults to |
Return Value
Type | Description |
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>
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
Name | Type | Description |
number | string | number | BN | The value in peb. |
unit | string | (optional, defaults to |
Return Value
Type | Description |
string | The string number. |
Examples
> caver.utils.convertFromPeb('1', 'KLAY')'0.000000000000000001'
caver.utils.unitMap
Shows all possible KLAY values and their amount in peb.
Return Value
Type | Description |
Object | With the following properties:
- |
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'}
caver.utils.klayUnit
Shows all KLAY units.
Return Value
Type | Description |
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 }}
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
Name | Type | Description |
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 |
Return Value
Type | Description |
string | The padded string. |
Examples
> caver.utils.padLeft('0x3456ff', 20)'0x000000000000003456ff'> caver.utils.padLeft(0x3456ff, 20)'0x000000000000003456ff'> caver.utils.padLeft('Hello', 20, 'x')'xxxxxxxxxxxxxxxHello'
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
Name | Type | Description |
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 |
Return Value
Type | Description |
string | The padded string. |
Examples
> caver.utils.padRight('0x3456ff', 20)'0x3456ff00000000000000'> caver.utils.padRight(0x3456ff, 20)'0x3456ff00000000000000'> caver.utils.padRight('Hello', 20, 'x')'Helloxxxxxxxxxxxxxxx'
caver.utils.toTwosComplement(num)
Converts a negative number into a two's complement.
Parameters
Name | Type | Description |
num | number | string | Bignumber | The number to convert. |
Return Value
Type | Description |
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'
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
Name | Type | Description |
transactionObject | object | An instance of Transaction to check contract deploy transaction or not. |
Return Value
Type | Description |
boolean |
|
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: '0x608060405234801561001057600080fd5b506101de806100206000396000f3006080604052600436106100615763ffffffff7c01000000000000000000000000000000000000000000000000000000006000350416631a39d8ef81146100805780636353586b146100a757806370a08231146100ca578063fd6b7ef8146100f8575b3360009081526001602052604081208054349081019091558154019055005b34801561008c57600080fd5b5061009561010d565b60408051918252519081900360200190f35b6100c873ffffffffffffffffffffffffffffffffffffffff60043516610113565b005b3480156100d657600080fd5b5061009573ffffffffffffffffffffffffffffffffffffffff60043516610147565b34801561010457600080fd5b506100c8610159565b60005481565b73ffffffffffffffffffffffffffffffffffffffff1660009081526001602052604081208054349081019091558154019055565b60016020526000908152604090205481565b336000908152600160205260408120805490829055908111156101af57604051339082156108fc029083906000818181858888f193505050501561019c576101af565b3360009081526001602052604090208190555b505600a165627a7a72305820627ca46bb09478a015762806cc00c431230501118c7c26c30ac58c4e09e51c4f0029',gas: 100000,}))true> caver.utils.isContractDeployment(caver.transaction.feeDelegatedSmartContractDeployWithRatio.create({from: '0x88e245dec96830f012f8fc1806bc623b3774560d',input: '0x608060405234801561001057600080fd5b506101de806100206000396000f3006080604052600436106100615763ffffffff7c01000000000000000000000000000000000000000000000000000000006000350416631a39d8ef81146100805780636353586b146100a757806370a08231146100ca578063fd6b7ef8146100f8575b3360009081526001602052604081208054349081019091558154019055005b34801561008c57600080fd5b5061009561010d565b60408051918252519081900360200190f35b6100c873ffffffffffffffffffffffffffffffffffffffff60043516610113565b005b3480156100d657600080fd5b5061009573ffffffffffffffffffffffffffffffffffffffff60043516610147565b34801561010457600080fd5b506100c8610159565b60005481565b73ffffffffffffffffffffffffffffffffffffffff1660009081526001602052604081208054349081019091558154019055565b60016020526000908152604090205481565b336000908152600160205260408120805490829055908111156101af57604051339082156108fc029083906000818181858888f193505050501561019c576101af565b3360009081526001602052604090208190555b505600a165627a7a72305820627ca46bb09478a015762806cc00c431230501118c7c26c30ac58c4e09e51c4f0029',gas: 100000,feeRatio: 30,}))true
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
Name | Type | Description |
publicKey | string | The publicKey to get x and y points. |
Return Value
Type | Description |
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']
caver.utils.isHexPrefixed(input)
Returns true
if the input is a 0x-prefixed hex string, otherwise it returns false
.
Parameters
Name | Type | Description |
input | string | The value to be determined if the parameter is 0x-prefixed hex string or not. |
Return Value
Type | Description |
boolean |
|
Examples
> caver.utils.isHexPrefixed('0xa5b0cd8c87e77879d64cc064ee239ed6f71cacf9')true> caver.utils.isHexPrefixed('0x1')true> caver.utils.isHexPrefixed('0xqwer')false> caver.utils.isHexPrefixed('1')false
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
Name | Type | Description |
input | string | string value to be prefixed with 0x. |
Return Value
Type | Description |
string | 0x-prefixed hex string is returned. |
Examples
> caver.utils.addHexPrefix('a5b0cd8c87e77879d64cc064ee239ed6f71cacf9')'0xa5b0cd8c87e77879d64cc064ee239ed6f71cacf9'> caver.utils.addHexPrefix('0xa5b0cd8c87e77879d64cc064ee239ed6f71cacf9')'0xa5b0cd8c87e77879d64cc064ee239ed6f71cacf9'
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
Name | Type | Description |
input | string | string to remove 0x prefix. |
Return Value
Type | Description |
string | A string stripped of 0x is returned. |
Examples
> caver.utils.stripHexPrefix('a5b0cd8c87e77879d64cc064ee239ed6f71cacf9')'a5b0cd8c87e77879d64cc064ee239ed6f71cacf9'> caver.utils.stripHexPrefix('0xa5b0cd8c87e77879d64cc064ee239ed6f71cacf9')'a5b0cd8c87e77879d64cc064ee239ed6f71cacf9'
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
Name | Type | Description |
input | Buffer | string | number | Array | BN | object | The value to be converted to a Buffer. |
Return Value
Type | Description |
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
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
Name | Type | Description |
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
> 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>
caver.utils.isValidHash(input)
Returns true
if the input is in 32-bytes hash format, otherwise it returns false
.
Parameters
Name | Type | Description |
input | string | The value to be examined that if it is in 32-bytes hash format or not. |
Return Value
Type | Description |
boolean |
|
Examples
// with '0x' hex prefix> caver.utils.isValidHash('0xe9a11d9ef95fb437f75d07ce768d43e74f158dd54b106e7d3746ce29d545b550')true// without '0x' hex prefix> caver.utils.isValidHash('e9a11d9ef95fb437f75d07ce768d43e74f158dd54b106e7d3746ce29d545b550')true> caver.utils.isValidHash('0x1')false
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
Name | Type | Description |
input | string | The value to be examined that if it is in the format of 0x-prefixed 32-bytes hash or not. |
Return Value
Type | Description |
boolean |
|
Examples
// with '0x' hex prefix> caver.utils.isValidHashStrict('0xe9a11d9ef95fb437f75d07ce768d43e74f158dd54b106e7d3746ce29d545b550')true// without '0x' hex prefix> caver.utils.isValidHashStrict('e9a11d9ef95fb437f75d07ce768d43e74f158dd54b106e7d3746ce29d545b550')false> caver.utils.isValidHashStrict('0x1')false
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
Name | Type | Description |
input | string | The value to be determined if the parameter is in the format of transaction hash or not. |
Return Value
Type | Description |
boolean |
|
Examples
// with '0x' hex prefix> caver.utils.isTxHash('0xe9a11d9ef95fb437f75d07ce768d43e74f158dd54b106e7d3746ce29d545b550')true// without '0x' hex prefix> caver.utils.isTxHash('e9a11d9ef95fb437f75d07ce768d43e74f158dd54b106e7d3746ce29d545b550')true> caver.utils.isTxHash('0x1')false
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
Name | Type | Description |
input | string | The value to be determined if the parameter is in the format of transaction hash or not. |
Return Value
Type | Description |
boolean |
|
Examples
// with '0x' hex prefix> caver.utils.isTxHashStrict('0xe9a11d9ef95fb437f75d07ce768d43e74f158dd54b106e7d3746ce29d545b550')true// without '0x' hex prefix> caver.utils.isTxHashStrict('e9a11d9ef95fb437f75d07ce768d43e74f158dd54b106e7d3746ce29d545b550')false> caver.utils.isTxHashStrict('0x1')false
caver.utils.isValidPrivateKey(privateKey)
Returns true
if privateKey
is valid, otherwise it returns false
.
Parameters
Name | Type | Description |
privateKey | string | A private key string to validate. |
Return Value
Type | Description |
boolean |
|
Examples
> caver.utils.isValidPrivateKey('0x{private key}')true> caver.utils.isValidPrivateKey('{private key}')true> caver.utils.isValidPrivateKey('a5b0cd8c87e77879d64cc064ee239ed6f71cacf9')false
caver.utils.isValidPublicKey(publicKey)
Returns true
if publicKey is valid, otherwise it returns false
.
Parameters
Name | Type | Description |
publicKey | string | A public key string to validate. |
Return Value
Type | Description |
boolean |
|
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')false
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
Name | Type | Description |
role | string | A role string to validate. |
Return Value
Type | Description |
boolean |
|
Examples
> caver.utils.isValidRole('roleTransactionKey')true> caver.utils.isValidRole('role')false
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
Name | Type | Description |
sig | object | Array | An instance of SignatureData or array of SignatureData to check empty or not. |
Return Value
Type | Description |
boolean |
|
Examples
> caver.utils.isEmptySig(caver.wallet.keyring.signatureData.emtpySig)true> caver.utils.isEmptySig([caver.wallet.keyring.signatureData.emtpySig])true
caver.utils.isKlaytnWalletKey(key)
Returns true
if key is in KlaytnWalletKey format, otherwise it returns false
.
Parameters
Name | Type | Description |
key | string | A key string to check in the format of KlaytnWalletKey or not. |
Return Value
Type | Description |
boolean |
|
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}')false
caver.utils.bufferToHex(buffer)
Converts buffer to 0x-prefixed hex string.
Parameters
Name | Type | Description |
buffer | Buffer | A buffer to convert to hex string. |
Return Value
Type | Description |
string | The 0x-prefixed hex string. |
Examples
> caver.utils.bufferToHex(Buffer.from('5b9ac8', 'hex'))'0x5b9ac8'> caver.utils.bufferToHex(Buffer.alloc(0))'0x'
caver.utils.parseKlaytnWalletKey(key)
Parses KlaytnWalletKey string to an array which includes "private key", "type", "address".
Parameters
Name | Type | Description |
key | string | A KlaytnWalletKey string. |
Return Value
Type | Description |
Array | The parsed KlaytnWalletKey. |
Examples
> caver.utils.parseKlaytnWalletKey('0x{private key}0x{type}0x{address in hex}')['0x{private key}','0x00','0x885ebdb17c221ef695936b18a0263d6399e14d60']
caver.utils.hashMessage(message)
Hashes message with Klaytn specific prefix: keccak256("\x19Klaytn Signed Message:\n" + len(message) + message))
Parameters
Name | Type | Description |
message | string | A message to hash. If it is a HEX string, it will be UTF-8 decoded first. |
Return Value
Type | Description |
string | The hashed message with Klaytn specific prefix. |
Examples
> caver.utils.hashMessage('Hello')'0x640bfab59b6e27468abd367888f4ab1a1c77aa2b45e76a1d3adcbd039c305917'
caver.utils.recover(message, signature [, preFixed])
Recovers the Klaytn address that was used to sign the given data.
Parameters
Name | Type | Description |
message | string | Either message or hashed message. |
signature | object | An instance of SignatureData. |
preFixed | boolean | (optional, default: |
Return Value
Type | Description |
string | The Klaytn address used to sign this data. |
Examples
> const sig = new caver.wallet.keyring.signatureData(['0x1b', '0x50a80...', '0x021de...'])> caver.utils.recover('message', sig)'0xe8b3a6ef12f9506e1df9fd445f9bb4488a482122'> caver.utils.recover('0xe960248437f2134a77a9aa0ebcbb6523aec095f23b02e25f16fd95e99b099daa', sig, true)'0xe8b3a6ef12f9506e1df9fd445f9bb4488a482122'
caver.utils.compressPublicKey(uncompressedPublicKey)
Compresses the uncompressed public key.
Parameters
Name | Type | Description |
uncompressedPublicKey | string | An uncompressed public key. |
Return Value
Type | Description |
string | A compressed public key. |
Examples
> caver.<