How to remove duplicates from front-end html array

This article mainly introduces the method of deduplicating front-end html arrays. It has certain reference value. Now I share it with you. Friends in need can refer to it

Array deduplication

Knowledge points used:

1:indexOf()

This method returns the index value of the firstoccurrence of elementin the array;

If there is, the index value will be returned normally;

If the retrieved content does not exist in the array , then return -1

2: for loop

Exercise: Array deduplication

//The first method

##

var aList = [1,2,3,4,4,3,2,1,2,3,4,5,6,5,5,3,3,4,2,1]; var aList2 = []; for (var i = 0 ; i < aList.length ; i ++) { 　　var value = aList[i] 　　if (aList.indexOf(value) + 1) { 　　　　console.log('重复了'，value) 　　} else { 　　　　aList2.push(value) 　　}　　　　　　　　 　　} 　　console.log(aList2)

// 第二种方法 var aList = [1,2,3,4,4,3,2,1,2,3,4,5,6,5,5,3,3,4,2,1]; for(var i=0;i
        

         Copy after login
        
       

// 第三种方法 var aList = [1,2,3,4,4,3,2,1,2,3,4,5,6,5,5,3,3,4,2,1]; for (var i = 0; i < aList.length; i++) { 　　var item = aList[i] if (newArray.indexOf(item) == -1) { 　　newArray.push(item) } else { 　　console.log('重复了',item) } }

htmlMaking login form

Basic elements of html form

The above is the detailed content of How to remove duplicates from front-end html array. For more information, please follow other related articles on the PHP Chinese website!