BigInt.asUintN()
Baseline
Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since 2020年9月.
BigInt.asUintN 静态方法将 BigInt 转换为一个 0 和 2^width-1 之间的无符号整数。
尝试一下
const U64_CEIL = 2n ** 64n;
console.log(BigInt.asUintN(64, U64_CEIL - 1n));
// 18446744073709551615n (2n ** 64n - 1n, the maximum non-wrapping value)
console.log(BigInt.asUintN(64, U64_CEIL));
// 0n (wraps to zero)
console.log(BigInt.asUintN(64, U64_CEIL + 1n));
// 1n
console.log(BigInt.asUintN(64, U64_CEIL * 2n));
// 0n (wraps on multiples)
console.log(BigInt.asUintN(64, U64_CEIL * -42n));
// 0n (also wraps on negative multiples)
语法
BigInt.asUintN(width, bigint);
参数
返回值
bigint 模 (modulo) 2^width 作为无符号整数的值。
示例
保持在 64 位范围内
BigInt.asUintN() 方法对于保持在 64 位 (64-bit) 算数范围内非常有用。
js
const max = 2n ** 64n - 1n;
BigInt.asUintN(64, max);
// ↪ 18446744073709551615n
BigInt.asUintN(64, max + 1n);
// ↪ 0n
// zero because of overflow
规范
| Specification |
|---|
| ECMAScript® 2026 Language Specification # sec-bigint.asuintn |
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