- DOCTYPE html>
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- content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=0,minimal-ui:ios">
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学无止境,永远对学习保持一种敬畏的态度! -
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- // indexOf:去重第一种方法
- var arr = [1, 5, 8, 9, 12, 26, 12, 5];
- var newArr = [];
- for (let i = 0; i < arr.length; i++) {
- if (newArr.indexOf(arr[i]) === -1) {
- newArr.push(arr[i]);
- }
- }
- console.log(newArr);
-
- // 双重for循环 :去重的第二种方法
- var arr = [1, 5, 8, 9, 12, 26, 12, 5];
- arr = arr.sort((a, b) => { return a - b })
- console.log(arr);
- for (let i = 0; i < arr.length; i++) {
- for (let j = i + 1; j < arr.length; j++) {
- if (arr[i] === arr[j]) {
- arr.splice(i, 1);
- j--;
- }
- }
- }
- console.log(arr);
-
- // es6新增set方法 :去重的第三种方法
- var arr = [1, 5, 8, 9, 12, 26, 12, 5];
- var newArr = new Set(arr);
- console.log(newArr);
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- function duplicates(arr) {
- var arr = [1, 2, 4, 4, 3, 3, 1, 5, 3]
- arr = arr.sort((a, b) => { return a - b })
- console.log(arr); // [1, 1, 2, 3, 3, 3, 4, 4, 5]
- let k = [];
- var flag = true;
- for (let i = 0; i < arr.length; i++) {
- for (let j = i + 1; j < arr.length; j++) {
- if (arr[i] === arr[j]) {
- flag = false;
- break;
- }
- }
- if (flag) {
- k.push(arr[i]);
- }
- }
- console.log(k);
- return k;
- }
- duplicates([1, 3, 4]);
- // console.log(duplicates([1, 3, 4]));
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