Home > Web Front-end > JS Tutorial > body text

Count the number of occurrences of repeated elements in JavaScript

亚连
Release: 2018-06-20 17:31:40
Original
1801 people have browsed it

The editor below will share with you an example of deduplicating a JavaScript array and counting the number of occurrences of repeated elements. It has a good reference value and I hope it will be helpful to everyone. Let’s follow the editor and take a look.

1. Method one

var arr = [1, 2, 3, 1, 2, 4];
  function arrayCnt(arr) {
  var newArr = [];
  for(var i = 0; i < arr.length; i++) {
   if(newArr.indexOf(arr[i]) == -1) {
   newArr.push(arr[i])
   }
  }
  var newarr2 = new Array(newArr.length);
  for(var t = 0; t < newarr2.length; t++) {
   newarr2[t] = 0;
  }
  for(var p = 0; p < newArr.length; p++) {
   for(var j = 0; j < arr.length; j++) {
   if(newArr[p] == arr[j]) {
    newarr2[p]++;
   }
   }
  }
  for(var m = 0; m < newArr.length; m++) {
   console.log(newArr[m] + "重复的次数为:" + newarr2[m]);
  }
  }
  arrayCnt(arr);
Copy after login

2. Method two (set method Remove duplicates)

var arr = [1, 2, 3, 1, 2, 4];
  function arrayCnt(arr) {
  var newArr = [];
  //使用set进行数组去重
  newArr = [...new Set(arr)];
  var newarr2 = new Array(newArr.length);
  for(var t = 0; t < newarr2.length; t++) {
   newarr2[t] = 0;
  }
  for(var p = 0; p < newArr.length; p++) {
   for(var j = 0; j < arr.length; j++) {
   if(newArr[p] == arr[j]) {
    newarr2[p]++;
   }
   }
  }
  for(var m = 0; m < newArr.length; m++) {
   console.log(newArr[m] + "重复的次数为:" + newarr2[m]);
  }
  }
  arrayCnt(arr);
Copy after login

The above is what I compiled for everyone. I hope it will be helpful to everyone in the future.

Related articles:

How to jump to the previous page in vue

How to implement dynamic loading using treeview in the Bootstrap framework Data

About website generation chapter directory code example

Detailed introduction to Vue data binding

Regarding the use of Vue high-order components

Is using JavaScript a better solution than asynchronous implementation?

Using Koa to build projects through Node.js

Detailed interpretation of React Native Flexbox layout

The above is the detailed content of Count the number of occurrences of repeated elements in JavaScript. For more information, please follow other related articles on the PHP Chinese website!

source:php.cn
Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
Popular Tutorials
More>
Latest Downloads
More>
Web Effects
Website Source Code
Website Materials
Front End Template
About us Disclaimer Sitemap
php.cn:Public welfare online PHP training,Help PHP learners grow quickly!