搜索
首页web前端js教程JavaScript数组去重方法总结

JavaScript数组去重方法总结

巴扎黑
巴扎黑
Aug 18, 2017 am 10:52 AM
javascriptjs

这篇文章主要介绍了JavaScript数组去重的十种方法,利用元素的属性和特性进行不同的去重方法，并实例演示如何测试去重超大数组，具体操作步骤大家可查看下文的详细讲解，感兴趣的小伙伴们可以参考一下。

一、前言：

我们在实际工作中，或者在面试找工作时，都会用到或者被问到一个问题，那就是“数组如何去重”。是的，这个问题有很多种解决方案，看看下面的十种方式吧！

二、数组去重方式大汇总：

Methods 1: 思路：定义一个新数组，并存放原数组的第一个元素，然后将元素组一一和新数组的元素对比，若不同则存放在新数组中。


function unique(arr){
 var res = [arr[0]];
 for(var i=1; i<arr.length; i++){
  var repeat = false;
  for(var j=0; j<res.length; j++){
   if(arr[i] === res[j]){
    repeat = true;
    break;
   }
  }
  if(!repeat){
   res.push(arr[i]);
  }
 }
 return res;
}
console.log(&#39;------------方法一---------------&#39;);

console.log(unique([1,1,2,3,5,3,1,5,6,7,4]));

Methods 2: 思路：先将原数组排序，在与相邻的进行比较，如果不同则存入新数组。


function unique2(arr){
 var arr2 = arr.sort();
 var res = [arr2[0]];
 for(var i=1; i<arr2.length; i++){
  if(arr2[i] !== res[res.length-1]){
   res.push(arr2[i]);
  }
 } 
 return res;
}

console.log(&#39;------------方法二---------------&#39;);

console.log(unique2([1,1,2,3,5,3,1,5,6,7,4]));

Methods 3: 利用对象属性存在的特性，如果没有该属性则存入新数组。


function unique3(arr){
 var res = [];
 var obj = {};
 for(var i=0; i<arr.length; i++){
  if( !obj[arr[i]] ){
   obj[arr[i]] = 1;
   res.push(arr[i]);
  }
 } 
 return res;
}

console.log(&#39;------------方法三---------------&#39;);

console.log(unique3([1,1,2,3,5,3,1,5,6,7,4]));

Methods 4: 利用数组的indexOf下标属性来查询。


function unique4(arr){
 var res = [];
 for(var i=0; i<arr.length; i++){
  if(res.indexOf(arr[i]) == -1){
   res.push(arr[i]);
  }
 }
 return res;
}

console.log(&#39;------------方法四---------------&#39;);

console.log(unique4([1,1,2,3,5,3,1,5,6,7,4]));

Methods 5: 利用数组原型对象上的includes方法。


function unique5(arr){
 var res = [];
 
 for(var i=0; i<arr.length; i++){
  if( !res.includes(arr[i]) ){ // 如果res新数组包含当前循环item
   res.push(arr[i]);
  }
 }
 return res;
}

console.log(&#39;------------方法五---------------&#39;);

console.log(unique5([1,1,2,3,5,3,1,5,6,7,4]));

Methods 6: 利用数组原型对象上的 filter 和 includes方法。


function unique6(arr){
 var res = [];
 
 res = arr.filter(function(item){
  return res.includes(item) ? &#39;&#39; : res.push(item);
 });
 return res;
}

console.log(&#39;------------方法六---------------&#39;);

console.log(unique6([1,1,2,3,5,3,1,5,6,7,4]));

Methods 7: 利用数组原型对象上的 forEach 和 includes方法。


function unique7(arr){
 var res = [];
 
 arr.forEach(function(item){
  res.includes(item) ? &#39;&#39; : res.push(item);
 }); 
 return res;
}

console.log(&#39;------------方法七---------------&#39;);

console.log(unique7([1,1,2,3,5,3,1,5,6,7,4]));

Methods 8: 利用数组原型对象上的 splice 方法。


function unique8(arr){
 var i,
  j,
  len = arr.length; 
 for(i = 0; i < len; i++){
  for(j = i + 1; j < len; j++){
   if(arr[i] == arr[j]){
    arr.splice(j,1);
    len--;
    j--;
   }
  }
 }
 return arr;
}

console.log(&#39;------------方法八---------------&#39;);

console.log(unique8([1,1,2,3,5,3,1,5,6,7,4]));

Methods 9: 利用数组原型对象上的 lastIndexOf 方法。


function unique9(arr){
 var res = []; 
 for(var i=0; i<arr.length; i++){
  res.lastIndexOf(arr[i]) !== -1 ? &#39;&#39; : res.push(arr[i]);
 }
 return res;
}

console.log(&#39;------------方法九---------------&#39;);

console.log(unique9([1,1,2,3,5,3,1,5,6,7,4]));

Methods 10: 利用 ES6的set 方法。


function unique10(arr){
 //Set数据结构，它类似于数组，其成员的值都是唯一的
 return Array.from(new Set(arr)); // 利用Array.from将Set结构转换成数组
}

console.log(&#39;------------方法十---------------&#39;);

console.log(unique10([1,1,2,3,5,3,1,5,6,7,4]));

 三、其他：

有意思的是，当我把数组的长度变得很大的时候（如下所示），测试了一下不同方法的执行时间长短，会发现方法三、四、五、六、七相对来说会更有优势，而方法八的执行速度似乎一直垫底。你也可以在你本地跑一下试试！

//测试用的超大数组
var arr = [1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6,7,4,1,1,2,3,5,3,1,5,6];
 
//这里只是举例方法三（如果你把所有方法放在一起测试，会更直观的看到执行时间的差异）


var time3 = new Date().getTime();
function unique3(arr){
 var res = [];
 var obj = {};
 for(var i=0; i<arr.length; i++){
  if( !obj[arr[i]] ){
   obj[arr[i]] = 1;
   res.push(arr[i]);
  }
 } 
 return res;
}

console.log(&#39;------------方法三---------------&#39;);

console.log( unique3(arr) );

console.log(&#39;3所花时间： &#39; + (new Date().getTime() - time3));

以上是JavaScript数组去重方法总结的详细内容。更多信息请关注PHP中文网其他相关文章！

声明
本文内容由网友自发贡献，版权归原作者所有，本站不承担相应法律责任。如您发现有涉嫌抄袭侵权的内容，请联系admin@php.cn
相关文章
Python和JavaScript的未来：趋势和预测Python和JavaScript的未来：趋势和预测Apr 27, 2025 am 12:21 AM

Python和JavaScript的未来趋势包括：1.Python将巩固在科学计算和AI领域的地位，2.JavaScript将推动Web技术发展，3.跨平台开发将成为热门，4.性能优化将是重点。两者都将继续在各自领域扩展应用场景，并在性能上有更多突破。

Python vs. JavaScript：开发环境和工具Python vs. JavaScript：开发环境和工具Apr 26, 2025 am 12:09 AM

Python和JavaScript在开发环境上的选择都很重要。1)Python的开发环境包括PyCharm、JupyterNotebook和Anaconda，适合数据科学和快速原型开发。2)JavaScript的开发环境包括Node.js、VSCode和Webpack，适用于前端和后端开发。根据项目需求选择合适的工具可以提高开发效率和项目成功率。

JavaScript是用C编写的吗？检查证据JavaScript是用C编写的吗？检查证据Apr 25, 2025 am 12:15 AM

是的，JavaScript的引擎核心是用C语言编写的。1）C语言提供了高效性能和底层控制，适合JavaScript引擎的开发。2）以V8引擎为例，其核心用C 编写，结合了C的效率和面向对象特性。3）JavaScript引擎的工作原理包括解析、编译和执行，C语言在这些过程中发挥关键作用。

JavaScript的角色：使网络交互和动态JavaScript的角色：使网络交互和动态Apr 24, 2025 am 12:12 AM

JavaScript是现代网站的核心，因为它增强了网页的交互性和动态性。1)它允许在不刷新页面的情况下改变内容，2)通过DOMAPI操作网页，3)支持复杂的交互效果如动画和拖放，4)优化性能和最佳实践提高用户体验。

C和JavaScript：连接解释C和JavaScript：连接解释Apr 23, 2025 am 12:07 AM

C 和JavaScript通过WebAssembly实现互操作性。1）C 代码编译成WebAssembly模块，引入到JavaScript环境中，增强计算能力。2）在游戏开发中，C 处理物理引擎和图形渲染，JavaScript负责游戏逻辑和用户界面。

从网站到应用程序：JavaScript的不同应用从网站到应用程序：JavaScript的不同应用Apr 22, 2025 am 12:02 AM

JavaScript在网站、移动应用、桌面应用和服务器端编程中均有广泛应用。1)在网站开发中，JavaScript与HTML、CSS一起操作DOM，实现动态效果，并支持如jQuery、React等框架。2)通过ReactNative和Ionic，JavaScript用于开发跨平台移动应用。3)Electron框架使JavaScript能构建桌面应用。4)Node.js让JavaScript在服务器端运行，支持高并发请求。

Python vs. JavaScript：比较用例和应用程序Python vs. JavaScript：比较用例和应用程序Apr 21, 2025 am 12:01 AM

Python更适合数据科学和自动化，JavaScript更适合前端和全栈开发。1.Python在数据科学和机器学习中表现出色，使用NumPy、Pandas等库进行数据处理和建模。2.Python在自动化和脚本编写方面简洁高效。3.JavaScript在前端开发中不可或缺，用于构建动态网页和单页面应用。4.JavaScript通过Node.js在后端开发中发挥作用，支持全栈开发。

C/C在JavaScript口译员和编译器中的作用C/C在JavaScript口译员和编译器中的作用Apr 20, 2025 am 12:01 AM

C和C 在JavaScript引擎中扮演了至关重要的角色，主要用于实现解释器和JIT编译器。 1）C 用于解析JavaScript源码并生成抽象语法树。 2）C 负责生成和执行字节码。 3）C 实现JIT编译器，在运行时优化和编译热点代码，显着提高JavaScript的执行效率。

See all articles

热AI工具

Undresser.AI Undress

Undresser.AI Undress

人工智能驱动的应用程序，用于创建逼真的裸体照片

AI Clothes Remover

AI Clothes Remover

用于从照片中去除衣服的在线人工智能工具。

Undress AI Tool

Undress AI Tool

免费脱衣服图片

Clothoff.io

Clothoff.io

AI脱衣机

Video Face Swap

Video Face Swap

使用我们完全免费的人工智能换脸工具轻松在任何视频中换脸！

显示更多

热门文章

刺客信条阴影：贝壳谜语解决方案
1 个月前ByDDD
Windows 11 KB5054979中的新功能以及如何解决更新问题
3 周前ByDDD
在哪里可以找到原子中的起重机控制钥匙卡
1 个月前ByDDD
如何修复KB5055523无法在Windows 11中安装？
2 周前ByDDD
Inzoi：如何申请学校和大学
3 周前ByDDD
显示更多

热工具

VSCode Windows 64位 下载

VSCode Windows 64位 下载

微软推出的免费、功能强大的一款IDE编辑器

SublimeText3 Linux新版

SublimeText3 Linux新版

SublimeText3 Linux最新版

记事本++7.3.1

记事本++7.3.1

好用且免费的代码编辑器

SublimeText3汉化版

SublimeText3汉化版

中文版，非常好用

mPDF

mPDF

mPDF是一个PHP库，可以从UTF-8编码的HTML生成PDF文件。原作者Ian Back编写mPDF以从他的网站上“即时”输出PDF文件，并处理不同的语言。与原始脚本如HTML2FPDF相比，它的速度较慢，并且在使用Unicode字体时生成的文件较大，但支持CSS样式等，并进行了大量增强。支持几乎所有语言，包括RTL（阿拉伯语和希伯来语）和CJK（中日韩）。支持嵌套的块级元素（如P、DIV），

显示更多

热门话题

gmail邮箱登陆入口在哪里
7753
15
Java教程
1643
14
CakePHP 教程
1398
52
Laravel 教程
1293
25
PHP教程
1234
29
显示更多