数组的解构赋值

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let [foo, [[bar], baz]] = [1, [[2], 3]];
foo // 1
bar // 2
baz // 3

let [ , , third] = ["foo", "bar", "baz"];
third // "baz"

let [x, , y] = [1, 2, 3];
x // 1
y // 3

let [head, ...tail] = [1, 2, 3, 4];
head // 1
tail // [2, 3, 4]

let [x, y, ...z] = ['a'];
x // "a"
y // undefined
z // []

对象的解构赋值

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let { bar, foo, baz } = { foo: 'aaa', bar: 'bbb' };
foo // "aaa"
bar // "bbb"
baz // undefined

//用途
const { log } = console;
log('hello') // hello

字符串的解构赋值

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let [a, b, c, d, e] = 'world';

//字符串有length属性
let {length : len} = 'hello';
len  // 5

函数参数的解构赋值

圆括号的解构赋值

数值和布尔值解构赋值

用途

从函数返回多个值

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function example() {
  return {
    foo: 1,
    bar: 2
  };
}
let { foo, bar } = example();

提取 JSON 数据

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let jsonData = {
  id: 42,
  status: "OK",
  data: [867, 5309]
};
let { id, status, data: number } = jsonData;
let { id, status, data } = jsonData;
console.log(id, status, number);
// 42, "OK", [867, 5309]
let { id, status, data } = jsonData;
console.log(id, status, data);
// 42, "OK", [867, 5309]

输入模块的指定方法

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//require加载方法
const { SourceMapConsumer, SourceNode } = require("source-map");