Uint.fromBigInt

Create Uint256 from JavaScript BigInt

Try it Live

Run Uint examples in the interactive playground

BigInt Values

JavaScript BigInt provides arbitrary precision integers:

// Small values
Uint.fromBigInt(0n)
Uint.fromBigInt(1n)
Uint.fromBigInt(255n)

// Large values
Uint.fromBigInt(2n ** 128n)
Uint.fromBigInt(2n ** 255n)

// Maximum
Uint.fromBigInt(2n ** 256n - 1n)

BigInt values must be non-negative and less than 2^256. Negative values and overflow throw errors.

Range Validation

Valid Range

// Minimum: 0
Uint.fromBigInt(0n)

// Maximum: 2^256 - 1
const max = 115792089237316195423570985008687907853269984665640564039457584007913129639935n
Uint.fromBigInt(max)

Out of Range

// Negative values throw
Uint.fromBigInt(-1n)        // Error: Value cannot be negative
Uint.fromBigInt(-100n)      // Error: Value cannot be negative

// Overflow throws
Uint.fromBigInt(2n ** 256n)     // Error: Value exceeds 2^256 - 1
Uint.fromBigInt(2n ** 257n)     // Error: Value exceeds 2^256 - 1

Usage Patterns

Computation Results

// BigInt arithmetic
const a = 100n
const b = 50n
const sum = Uint.fromBigInt(a + b)        // 150
const product = Uint.fromBigInt(a * b)    // 5000

// With validation
function safeFromBigInt(value: bigint): BrandedUint256 | null {
  if (value < 0n || value >= 2n ** 256n) {
    return null
  }
  return Uint.fromBigInt(value)
}

Constants

// Common Ethereum constants
const ONE_ETHER = Uint.fromBigInt(10n ** 18n)
const ONE_GWEI = Uint.fromBigInt(10n ** 9n)
const MAX_UINT256 = Uint.fromBigInt(2n ** 256n - 1n)
const MAX_UINT128 = Uint.fromBigInt(2n ** 128n - 1n)

Parsing Large Numbers

// JSON doesn't support BigInt, must parse strings
interface ApiResponse {
  balance: string  // BigInt serialized as string
}

function parseBalance(data: ApiResponse): BrandedUint256 {
  const balanceBigInt = BigInt(data.balance)
  return Uint.fromBigInt(balanceBigInt)
}

See Also

• from - Universal constructor
• toBigInt - Convert to BigInt
• fromNumber - From number