How to implement array deduplication in es5 and es6

In es5, you can use the for statement and indexOf() function to achieve array deduplication. The syntax is "for(i=0;i

The operating environment of this tutorial: Windows 7 system, ECMAScript version 6, Dell G3 computer.

es5 array deduplication

##indexOf method

Use indexOf (can return the position where a specified string value first appears in the string, if it appears for the first time, return -1)

	var arr = [1,2,3,1,3,4,5];
	Array.prototype.myInfo = function(){
		var newArr = [];
		for(var i=0;i<arr.length var if newarr return console.log><p><img src="/static/imghwm/default1.png" data-src="https://img.php.cn/upload/article/000/000/024/356e180a6b80e6d664a8d03b344e4adc-0.png?x-oss-process=image/resize,p_40" class="lazy" alt="How to implement array deduplication in es5 and es6"></p>
<h2>
<a id="es6__21"></a>es6 Array deduplication<strong></strong>
</h2>
<p><a id="1_Arrayfrom__Set_22"></a><strong>1. Array.from and Set<span style="font-size: 16px;"></span></strong></p>Set does not allow duplicate elements<p></p>
<pre class="brush:php;toolbar:false">	let arr = [1,2,1,2,3];
	let result = new Set(arr);

	console.log(result); 			
	console.log(Array.from(result));

## 2. rest and Setrest method operator is "

…

"

…

Strips characters from the array

	let arr = [1,2,1,2,3];
	let result = new Set(arr);

	console.log(result); 	
	console.log(...result); 		
	console.log([...result]); 			

	console.log([...new Set(arr)]);

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