JS convert pseudo array to array

In JS, pseudo-arrays are very common, also called array-like. So it is very important to understand and understand good pseudo-arrays. This article will explain in detail what a pseudo-array is and how to convert a pseudo-array into a real array in ES5 and ES6 respectively. What is a pseudo-array? The main characteristic of a pseudo-array: it is an object, and that object has a length property.

Pseudo-array of object type

let obj={

        0:"aaa",

        1:"bbb",

        2:"ccc",

        3:"ddd",

        length:4

       }

//    let arr=[];

//    arr.push.apply(arr,obj);

//    console.log(arr,arr instanceof Array);// ["aaa", "bbb", "ccc", "ddd"] true

Using the Array.from() method in ES6

 let obj={

        0:"aaa",

        1:"bbb",

        2:"ccc",

        3:"ddd",

        length:4

       }

       let b=Array.from(obj);

       console.log(b,b instanceof Array);

Using the Array.prototype.slice.call() method in ES6

 let obj={

        0:"aaa",

        1:"bbb",

        2:"ccc",

        3:"ddd",

        length:4

       }

       let b=Array.prototype.slice.call(obj);

       console.log(b,b instanceof Array);

Strings are converted to arrays using spread operator

let str="hello"

       console.log([...str])//["h", "e", "l", "l", "o"]