解构-赋值

1. 数组解构

let first,second
[first, second] = [1, 2];
logd(first); // 输出: 1
logd(second); // 输出: 2

2. 稀疏数组解构

let a,c
[a, , c] = [1, undefined, 3];
logd(a); // 输出: 1
logd(c); // 输出: 3

3. 字符串解构

let char1, char2
[char1, char2] = "ab";
logd(char1); // 输出: a
logd(char2); // 输出: b

4. 对象解构

• 需要在外层加()

let name, age
({name, age} = {name: "Alice", age: 25})
logd(name); // 输出: Alice
logd(age); // 输出: 25

let c,d,e
({c, x:d, e} = {c:7, x:8})
logd(c,d,e)  // 输出: 7, 8, undefined

5. 链式解构

• 数组

let a,b,c,d;
[a,b] = [c,d] = [1,2];
logd(a,b,c,d) // 输出: 1,2,1,2

• 对象

let a,b,c,d;
({a,b} = {c,d} = {a:1,b:2,c:3,d:4})
logd(a,b,c,d) // 输出: 1,2,3,4

6. 嵌套解构

let e, f, g, h, i;
[e, {x: f, g}] = [9, {x: 10}];
({h, x: [i]} = {h: 11, x: [12]});
logd(e, f, g, h, i) // 输出: 9, 10, undefined, 11, 12

8. 默认值

let a, b, c, d, e, f;
({a = 1, b = 0, z: c = 3} = {b: 2, z: undefined});
[d = 0, e = 5, f = 6] = [4, , undefined];
logd(a, b, c, d, e, f) // 输出: 1, 2, 3, 4, 5, 6