es5 实现方法
for 循环 + indexOf
- function unique(arr) {
- var uniqueArr = [],
- len = arr.length
- for (var i = 0; i < len; i++) {
- if (uniqueArr.indexOf(arr[i]) == -1) {
- uniqueArr.push(arr[i])
- }
- }
- return uniqueArr
- }
- var arr = [1, 2, 3, 1, 5, "1"]
- var uniqueArr = unique(arr)
- console.log(arr) //[1, 2, 3, 1, 5, "1"]
- console.log(uniqueArr) //[ 1, 2, 3, 5, '1' ]
排序后去重
- function unique(arr) {
- var uniqueArr = [],
- sortArr = arr.concat().sort(),
- len = sortArr.length,
- prev
- for (var i = 0; i < len; i++) {
- if (!i || prev !== sortArr[i]) {
- uniqueArr.push(sortArr[i])
- }
- prev = sortArr[i]
- }
- return uniqueArr
- }
- var arr = [1, 2, 3, 1, 5, "1"]
- var uniqueArr = unique(arr)
- console.log(arr) //[ 1, 2, 3, 1, 5, '1' ]
- console.log(uniqueArr) //[ 1, '1', 2, 3, 5 ]
利用对象
- function unique(arr) {
- var uniqueArr = [],
- obj = {},
- len = arr.length
- for (var i = 0; i < len; i++) {
- obj[typeof arr[i] + arr[i]] = arr[i]
- }
- for (var i in obj) {
- uniqueArr.push(obj[i])
- }
- console.log(obj) //{ number1: 1, number2: 2, number3: 3, number5: 5, string1: '1' }
- return uniqueArr
- }
- var arr = [1, 2, 3, 1, 5, "1"]
- var uniqueArr = unique(arr)
- console.log(arr) // [1, 2, 3, 1, 5, "1"]
- console.log(uniqueArr) //[ 1, 2, 3, 5, '1' ]
来源: http://www.jianshu.com/p/8369c8d65792