1.将字符串，对象等作为伪数组转换成数组: Array.from()   

将伪数组转变成数组，就是只要有length的长度就可以转成数组   --ES6

let str = '12345'
console.log(Array.from(str))
let obj={0:'a',1:'b',length:2}
console.log(Array.from(obj))
//这样将字符串每个变为索引元素

2.将一组值转换成数组，类似声明为数组 --es6 

Array.of()

let str='11'

console.log(Array.of(str))  //['11']

console.log(new Array('11')) //['11']

//但是参数问题会引起重载   加字符串是数组，不加是是长度
 console.log(new Array(2)) //enmpty x2
console.log(Array.of(2))  //['2']

let str='11'

console.log(Array.of(str))  //['11']

console.log(new Array('11')) //['11']

//但是参数问题会引起重载   加字符串是数组，不加是是长度
 console.log(new Array(2)) //enmpty x2
console.log(Array.of(2))  //['2']