静态方法

from()

TIP

静态方法从可迭代或类数组对象创建一个新的浅拷贝的数组实例

// 数组及数组元素
console.log(Array.from('foo'));
// Expected output: Array ["f", "o", "o"]

console.log(Array.from([1, 2, 3], (x) => x + x));
// Expected output: Array [2, 4, 6]

fromAsync()

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静态方法可以由一个异步可迭代对象、可迭代对象或类数组对象创建一个新的、浅拷贝的 Array 实例

// 从异步可迭代对象创建数组
const asyncIterable = (async function* () {
  for (let i = 0; i < 5; i++) {
    await new Promise((resolve) => setTimeout(resolve, 10 * i));
    yield i;
  }
})();

// 从同步可迭代对象创建数组
Array.fromAsync(
  new Map([
    [1, 2],
    [3, 4],
  ]),
).then((array) => console.log(array));

// 从产生 promise 的同步可迭代对象创建数组
Array.fromAsync(
  new Set([Promise.resolve(1), Promise.resolve(2), Promise.resolve(3)]),
).then((array) => console.log(array));
// [1, 2, 3]

// 从 promise 的类数组对象创建数组
Array.fromAsync({
  length: 3,
  0: Promise.resolve(1),
  1: Promise.resolve(2),
  2: Promise.resolve(3),
}).then((array) => console.log(array));
// [1, 2, 3]

isArray()

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静态方法用于确定传递的值是否是一个数组

console.log(Array.isArray([1, 3, 5]));
// Expected output: true

console.log(Array.isArray('[]'));
// Expected output: false

console.log(Array.isArray(new Array(5)));
// Expected output: true

console.log(Array.isArray(new Int16Array([15, 33])));
// Expected output: false

of()

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静态方法通过可变数量的参数创建一个新的 Array 实例，而不考虑参数的数量或类型

console.log(Array.of('foo', 2, 'bar', true));
// Expected output: Array ["foo", 2, "bar", true]

console.log(Array.of());
// Expected output: Array []