数组常用方法

let arr = [1, 2, 3];
let arr2 = [...arr];  //等同于 let arr2 = Array.from(arr);

let [a, b, c] = [1, 2, 3];   //a=1, b=2, c=3

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

let [head, ...tail] = [1, 2, 3, 4];  //head=1, tail=234

let [x, y, ...z] = ['a'];  //x=a, y=undefined, z=[], 如果解构不成功,变量的值就等于undefined

let [x, y = 'b'] = ['a']; // x='a', y='b',解构赋值允许指定默

// 解构赋值超强
const {
    form: { validateFields }
} = this;
    validateFields((err, values) => {
        if (!err) {
          // eslint-disable-next-line no-console
          console.log("Received values of form: ", values);    
        }
    });