This article mainly introduces the JS method of finding repeated elements in an array, and compares and analyzes JavaScript's traversal, judgment, sorting and other related operation skills for arrays based on specific examples. Friends in need can refer to it
The example in this article describes the method of finding duplicate elements in an array using JS. Share it with everyone for your reference, the details are as follows:
The data type of JS has an array. Today we will talk about a kind of processing of arrays. I believe many people have encountered finding unique elements from an array, but what I encountered was finding duplicate elements from an array.
There are many ways to find non-repeating elements from a js array. Here is one:
<!DOCTYPE html>
<html>
<body>
<script>
Array.prototype.deleteEle=function(){
var newArr = this;
for (var i=newArr.length-1; i>=0; i--)
{
var targetNode = newArr[i];
for (var j=0; j<i; j++)
{
if(targetNode == newArr[j]){
newArr.splice(i,1);
break;
}
}
}
return newArr;
}
var arr = ["a","b","c","c","ab","d","ab","d","c"];
console.log(arr.deleteEle());
</script>
</body>
</html>The running effect is as follows:
Here is another way to find duplicate elements from a js array:
<!DOCTYPE html>
<html>
<body>
<script>
var a = [5,4,3,2,1,2,3,2,1,];
Array.prototype.duplicate=function() {
var tmp = [];
this.concat().sort().sort(function(a,b){
if(a==b && tmp.indexOf(a) === -1) tmp.push(a);
});
return tmp;
}
console.log(a.duplicate())
</script>
</body>
</html>Running renderings as follows:
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