JavaScript 数组去重并统计重复元素出现的次数实例

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);

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);