Detailed explanation of js array deduplication and sorting

This article mainly shares with you the detailed explanation of deduplication and sorting of js arrays. I hope it can help you.

1. Use indexOf to check whether it exists. If it does not exist, it is not added.

		var arr = ['aa','aa','aa','bb','bb',3,5,8,9,4,5,4];

		function unique(arr){
			var newArr = [];
			for(var i in arr){
				if(newArr.indexOf(arr[i]) === -1){
					newArr.push(arr[i])
				}
			}
			return newArr;
		}

2. Use filter to filter, and then use indexOf to check whether it exists.

		function unique1(arr){
			function aa(item, index, array){
				return array.indexOf(item) === index;  // 当前值在原数组中第一次出现的位置 === 他的索引，就证明它不是重复的，然后就返回去
			}
			var res = arr.filter(aa);
			return res
		}

Sort

		var conf = {
			compare : function(property){
				return function(a,b){
			        var value1 = a[property];
			        var value2 = b[property];
			        return value1 - value2;
			    }
			},
			sortList:function(arr,str){//数组排序
				if(Object.prototype.toString.call(arr).slice(8,-1) ==='Array'){
					if(str){
						var returnArr = arr.sort(this.compare(str));
					}else{
						var returnArr = arr.sort(this.sort(str));
					}
					
					return returnArr;
				}else{
					return arr;
				}
			},
			sort:function(arr){//数组排序
				if(Object.prototype.toString.call(arr).slice(8,-1) ==='Array'){
					var array = [];
					for(var i in arr){
						array.push(arr[i]);
					}
					for (var i = 1; i < array.length; i++) {
						var key = array[i];
						var j = i - 1;
							while (j >= 0 && array[j] > key) {
							array[j + 1] = array[j];
							j--;
						}
						array[j + 1] = key;
					}
					return array;
				}else{
					return arr;
				}
			}
		}
		

		var arr = [{a:2,b:&#39;x2&#39;},{a:3,b:&#39;x3&#39;},{a:1,b:&#39;x1&#39;}];
		var arr2 = [4,1,3,5,2]

		var newArr = conf.sortList(arr,&#39;a&#39;);
		var v = conf.sortList(arr2);
		console.log(newArr)
		console.log(v)

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