解构赋值

var = "hello world";

左边是变量名，右边可以是任意的数据类型。

数组的解构赋值

可以为多个变量赋值，例如：

var = 1;
var = 2;
var = 3;

let [ , , ] = [1, 2, 3];

(1)嵌套数组的解构

let [ , [[ ], ]] = [1, [[2], 3]];
console.log( ); 
console.log( );
console.log( ); 
let [ , , ] = [1, 2, 3];
console.log( );
let [ , , ] = [1, 2, 3];
console.log( );
console.log( );

(2)数组解构的默认值

var [ , ] = [];
.log( ); // undefined
.log( ); // undefined
// 有默认值
var [ = 1, = 2] = [];
console.log( ); 
console.log( );
var [ = 1, = 2] = [3, 4];
console.log( );
console.log( );

(3)对象的解构赋值

var { : , : } = { : "zhangsan", : 20 };
console.log( );
console.log( );

(4)嵌套对象的解构

var = {
: ["张三", { : "二狗子" }]
}
// 属性名跟属性值的变量名不相同时
var { : [ , { : }] } = ;
console.log( ); 
console.log( ); 
// 属性名跟属性值的变量名相同时
var { : [ , { }] } = ;
console.log( );
console.log( );

 

转载于:https://www.cnblogs.com/zhangmeijuan/p/7259466.html