解构赋值 - 数组的解构赋值

 

        let [foo, [[bar], baz]] = [1, [[2], 3]];
        console.log(foo)  // 1
        console.log(bar) // 2
        console.log(baz) // 3

        let [a, ...b] = [1, 2, 3, 4];
        console.log(a)  // 1
        console.log(b) //[2, 3, 4]

•   不存在为undefined

        let [foo] = [];
        let [bar, baz] = [1];

        console.log(foo)  // undefined
        console.log(bar) //1
        console.log(baz) //undefined

• 　　默认值

       let [x, y = 'b'] = ['a'];
        console.log(x)  // a
        console.log(y) //b

• 　　严格相等运算符===

        let [x = 1] = [undefined];
        let [y = 1] = [null];
        console.log(x)  // 1
        console.log(y) // null