我有两个JavaScript数组:

var array1 = ["Vijendra","Singh"];
var array2 = ["Singh", "Shakya"];

我希望输出为:

var array3 = ["Vijendra","Singh","Shakya"];

输出数组应删除重复的单词。

如何在JavaScript中合并两个数组,以便从每个数组中只获得唯一的项目,其顺序与它们插入原始数组的顺序相同?


当前回答

var array1=[“一”,“二”];var array2=[“two”,“three”];var collectionOfTwoArrays=[…array1,…array2];var uniqueList=array=>[…new Set(array)];console.log('集合:');console.log(collectionOfTwoArrays);console.log('没有重复项的集合:');console.log(uniqueList(collectionOfTwoArrays));

其他回答

表演

今天2020.10.15我在Chrome v86、Safari v13.1.2和Firefox v81上对MacOs HighSierra 10.13.6进行了测试,以确定所选的解决方案。

后果

适用于所有浏览器

解决方案H快速/最快解决方案L很快解决方案D在大型阵列的chrome上速度最快解决方案G在小阵列上速度很快解决方案M对于小型阵列来说是最慢的解决方案E对于大型阵列来说是最慢的

细节

我执行两个测试用例:

对于2元素数组-您可以在此处运行对于10000个元素数组-您可以在这里运行

关于解决方案A.BCDEGHJLM在下面的片段中显示

// https://stackoverflow.com/a/10499519/860099函数A(arr1,arr2){返回_并集(arr1,arr2)}// https://stackoverflow.com/a/53149853/860099函数B(arr1,arr2){return _.unionWith(arr1,arr2,_.isEqual);}// https://stackoverflow.com/a/27664971/860099函数C(arr1,arr2){return[…new Set([…arr1,…arr2])]}// https://stackoverflow.com/a/48130841/860099函数D(arr1,arr2){return Array.from(新集合(arr1.concat(arr2)))}// https://stackoverflow.com/a/23080662/860099函数E(arr1,arr2){return arr1.concat(arr2.filter((项)=>arr1.indexOf(项)<0))}// https://stackoverflow.com/a/28631880/860099函数G(arr1,arr2){var哈希={};变量i;对于(i=0;i<arr1.length;i++){hash[arr1[i]=真;}对于(i=0;i<arr2.length;i++){hash[ar2[i]=真;}return Object.keys(哈希);}// https://stackoverflow.com/a/13847481/860099函数H(a,b){var哈希={};var ret=[];对于(var i=0;i<a.length;i++){变量e=a[i];if(!hash[e]){hash[e]=真;ret.push(e);}}对于(var i=0;i<b.length;i++){变量e=b[i];if(!hash[e]){hash[e]=真;ret.push(e);}}返回ret;}// https://stackoverflow.com/a/1584377/860099函数J(arr1,arr2){函数arrayUnique(数组){var a=array.contat();对于(var i=0;i<a.length;++i){对于(var j=i+1;j<a.length;++j){如果(a[i]===a[j])a.接头(j-,1);}}返回a;}return arrayUnique(arr1.concat(arr2));}// https://stackoverflow.com/a/25120770/860099函数L(array1,array2){常量数组3=数组1.slice(0);设len1=阵列长度;设len2=阵列2.length;常量assoc={};而(len1--){assoc[array1[len1]]=空;}而(len2--){设itm=array2[len2];if(assoc[itm]==未定义){//消除indexOf调用array3.push(itm);assoc[itm]=空;}}返回数组3;}// https://stackoverflow.com/a/39336712/860099函数M(arr1,arr2){常量comp=f=>g=>x=>f(g(x));常量应用=f=>a=>f(a);常量flip=f=>b=>a=>f(a)(b);常量concat=xs=>y=>xs.contat(y);const afrom=应用(Array.from);const createSet=xs=>新集合(xs);常量过滤器=f=>xs=>xs.filter(apply(f));常量重复数据删除=comp(afrom)(createSet);常量并集=xs=>ys=>{const zs=创建集(xs);返回凹面(xs)(滤波器(x=>zs.has(x)? 假的:zs.add(x))(ys));}返回联合(重复数据消除(arr1))(arr2)}// -------------//测试// -------------var array1=[“Vijendra”,“Singh”];var array2=[“Singh”,“Shakya”];[A、B、C、D、E、G、H、J、L、M]。对于每个(f=>{console.log(`${f.name}[${f([…array1],[…array2])}]`);})<script src=“https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.20/lodash.min.js“integrity=”sha512-90vH1Z83AJY9DmlWa8WkjkV79yfS2n2Oxhsi2dZbIv0nC4E6m5AbH8Nh156kkM7JePmqD6tcZsfad1ueoaovww==“crossrorigin=”匿名“></script>此代码段仅显示性能测试中使用的函数-它本身不执行测试!

下面是chrome的示例测试运行

更新

我删除了案例F、I、K,因为它们修改了输入数组,基准测试给出了错误的结果

Use:

Array.prototype.merge = function (arr) {
    var key;
    for(key in arr) 
        this[key] = arr[key];
};

这是我的解决方案https://gist.github.com/4692150深度相等且易于使用的结果:

function merge_arrays(arr1,arr2)
{
   ... 
   return {first:firstPart,common:commonString,second:secondPart,full:finalString}; 
}

console.log(merge_arrays(
[
[1,"10:55"] ,
[2,"10:55"] ,
[3,"10:55"]
],[
[3,"10:55"] ,
[4,"10:55"] ,
[5,"10:55"]
]).second);

result:
[
[4,"10:55"] ,
[5,"10:55"]
]

使用Undercore.js或Lo Dash,您可以执行以下操作:

console.log(_.union([1,2,3],[101,2,1,10],[2,1]));<script src=“https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.15/lodash.min.js“></script>

http://underscorejs.org/#union

http://lodash.com/docs#union

看起来接受的答案是我测试中最慢的;

注意,我正在按Key合并2个对象数组

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width">
  <title>JS Bin</title>
</head>
<body>
<button type='button' onclick='doit()'>do it</button>
<script>
function doit(){
    var items = [];
    var items2 = [];
    var itemskeys = {};
    for(var i = 0; i < 10000; i++){
        items.push({K:i, C:"123"});
        itemskeys[i] = i;
    }

    for(var i = 9000; i < 11000; i++){
        items2.push({K:i, C:"123"});
    }

    console.time('merge');
    var res = items.slice(0);

    //method1();
    method0();
    //method2();

    console.log(res.length);
    console.timeEnd('merge');

    function method0(){
        for(var i = 0; i < items2.length; i++){
            var isok = 1;
            var k = items2[i].K;
            if(itemskeys[k] == null){
                itemskeys[i] = res.length;
                res.push(items2[i]);
            }
        }
    }

    function method1(){
        for(var i = 0; i < items2.length; i++){
            var isok = 1;
            var k = items2[i].K;

            for(var j = 0; j < items.length; j++){
                if(items[j].K == k){
                    isok = 0;
                    break;
                }
            }

            if(isok) res.push(items2[i]);
        }  
    }

    function method2(){
        res = res.concat(items2);
        for(var i = 0; i < res.length; ++i) {
            for(var j = i+1; j < res.length; ++j) {
                if(res[i].K === res[j].K)
                    res.splice(j--, 1);
            }
        }
    }
}
</script>
</body>
</html>