数组去重

Posted 2021-02-28 sheep2

个人总结

数组去重

let ary = [2, 6, 5, 5, 99, 65, 5, 2, 989, 23, 65, 6 ]

function getDiff(arr) {
    let obj = {}
    for (let i = 0; i < arr.length; i++) {
	let temp = arr[i]
	if (obj[temp] === temp && temp !== undefined) {
	    arr.splice(i, 1)
	    i--	//数组长度变短 索引回到前一位
	    continue //跳出本次循环
	}
	obj[temp] = temp
    }
    obj = null
    return arr
}

const resArr = getDiff(ary)
console.log(resArr) //[2, 6, 5, 99, 65, 989, 23]

在20个数中取得不同的5个数

let arr = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20]

function getNums(arr, count) {
    let newArr = []
    for (let i = 0; i < count; i++) {
	let num = Math.floor(Math.random() * arr.length)
	newArr.push(arr[num])
	//arr.splice(num, 1) 
	arr[num] = arr[arr.length - 1]
	arr.length = arr.length - 1
    }
    return newArr
}

const res = getNums(arr, 5)
console.log(res)