一、Array对象方法 1.Array.from():将伪数组或可遍历对象转换为真正的数组(字符串,对象,类数组,set,map等) let str = '1234'; const arr1 =Array.from(str); console.log(arr1);//(4) ['1', '2', '3', '4'] const Arr = { 2:'a', 3:'b', length:4, } console.log(Array.from(Arr));// (4) [undefined, undefined, 'a', 'b'] ...