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数组去重 #7

Open ziwei3749 opened 6 years ago

ziwei3749 commented 6 years ago

数组去重

数组去重的ES6版本

var arr = [1,2,3,3,4,2,1]

var newArr = [...new Set(arr)]

数组去重的indexOf版本

var arr = [1,2,3,3,4,2,1]

var newArr = []
arr.forEach(item => {
    if(newArr.indexOf(item) == -1){
        newArr.push(item)
    }
})

2个数组,可以通过indexOf去重

注意遍历length较长的那个数组

var arr1 = [1,2,3,4]
var arr2 = [1,2,3,4,5,6]

var newArr = []
arr2.forEach(item => {
    if(arr1.indexOf(item) == -1){
        newArr.push(item)
    }
})