JavaScript 内置对象 BigInt详细解析

const theBiggestInt = 9007199254740991n;
const alsoHuge = BigInt(9007199254740991);
// ↪ 9007199254740991n
const hugeString = BigInt("9007199254740991");
// ↪ 9007199254740991n
const hugeHex = BigInt("0x1fffffffffffff");
// ↪ 9007199254740991n
const hugeBin = BigInt("0b11111111111111111111111111111111111111111111111111111");
// ↪ 9007199254740991n

const max = 2n ** (64n - 1n) - 1n;

BigInt.asIntN(64, max);
// ↪ 9223372036854775807n

BigInt.asIntN(64, max + 1n);
// ↪ -9223372036854775808n
// negative because of overflow

const max = 2n ** 64n - 1n;

function check64bit(number) {
  (number > max) ?
    console.log('Number doesn\'t fit in unsigned 64-bit integer!') :
    console.log(BigInt.asUintN(64, number));
}
check64bit(2n ** 64n);
// expected output: "Number doesn't fit in unsigned 64-bit integer!"
check64bit(2n ** 32n);
// expected output: 4294967296n

const bigint = 123456789123456789n;

// German uses period for thousands
console.log(bigint.toLocaleString('de-DE'));
// expected output: "123.456.789.123.456.789"

var bigint = 123456789123456789n;

// German uses period for thousands
console.log(bigint.toLocaleString('de-DE'));
// → 123.456.789.123.456.789

// Arabic in most Arabic speaking countries uses Eastern Arabic digits
console.log(bigint.toLocaleString('ar-EG'));
// → ١٢٣٬٤٥٦٬٧٨٩٬١٢٣٬٤٥٦٬٧٨٩

// India uses thousands/lakh/crore separators
console.log(bigint.toLocaleString('en-IN'));
// → 1,23,45,67,89,12,34,56,789
// the nu extension key requests a numbering system, e.g. Chinese decimal
console.log(bigint.toLocaleString('zh-Hans-CN-u-nu-hanidec'));
// → 一二三,四五六,七八九,一二三,四五六,七八九
// when requesting a language that may not be supported, such as
// Balinese, include a fallback language, in this case Indonesian
console.log(bigint.toLocaleString(['ban', 'id']));
// → 123.456.789.123.456.789

console.log(1024n.toString());
// expected output: "1024"
console.log(1024n.toString(2));
// expected output: "10000000000"
console.log(1024n.toString(16));
// expected output: "400"

console.log(typeof Object(1n));
// expected output: "object"

console.log(typeof Object(1n).valueOf());
// expected output: "bigint"