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

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>

其他回答

下面是一个简单的例子:

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

var uniqueList = unique(["AAPL", "MSFT"].concat(["MSFT", "BBEP", "GE"]));

我们定义unique(array)来删除冗余元素,并使用concat函数来组合两个数组。

这是我的第二个答案,但我相信最快的答案是什么?我希望有人帮我检查并在评论中回复。

我的第一次尝试达到了99k操作/秒,这一次的复测是390k操作/每秒,而另一次领先的jsperf测试是140k(对我来说)。

http://jsperf.com/merge-two-arrays-keeping-only-unique-values/26

这次我尝试尽可能减少阵列交互,看起来我获得了一些性能。

function findMerge(a1, a2) {
    var len1 = a1.length;

    for (var x = 0; x < a2.length; x++) {
        var found = false;

        for (var y = 0; y < len1; y++) {
            if (a2[x] === a1[y]) {
                found = true;
                break;
            }
        }

        if(!found){
            a1.push(a2.splice(x--, 1)[0]);
        }
    }

    return a1;
}

编辑:我对我的功能做了一些更改,与jsperf站点上的其他功能相比,性能非常出色。

新解决方案(使用Array.prototype.indexOf和Array.prototype.cocat):

Array.prototype.uniqueMerge = function( a ) {
    for ( var nonDuplicates = [], i = 0, l = a.length; i<l; ++i ) {
        if ( this.indexOf( a[i] ) === -1 ) {
            nonDuplicates.push( a[i] );
        }
    }
    return this.concat( nonDuplicates )
};

用法:

>>> ['Vijendra', 'Singh'].uniqueMerge(['Singh', 'Shakya'])
["Vijendra", "Singh", "Shakya"]

Array.prototype.indexOf(用于internet explorer):

Array.prototype.indexOf = Array.prototype.indexOf || function(elt)
  {
    var len = this.length >>> 0;

    var from = Number(arguments[1]) || 0;
    from = (from < 0) ? Math.ceil(from): Math.floor(from); 
    if (from < 0)from += len;

    for (; from < len; from++)
    {
      if (from in this && this[from] === elt)return from;
    }
    return -1;
  };

合并无限数量的数组或非数组并保持其唯一性:

function flatMerge() {
    return Array.prototype.reduce.call(arguments, function (result, current) {
        if (!(current instanceof Array)) {
            if (result.indexOf(current) === -1) {
                result.push(current);
            }
        } else {
            current.forEach(function (value) {
                console.log(value);
                if (result.indexOf(value) === -1) {
                    result.push(value);
                }
            });
        }
        return result;
    }, []);
}

flatMerge([1,2,3], 4, 4, [3, 2, 1, 5], [7, 6, 8, 9], 5, [4], 2, [3, 2, 5]);
// [1, 2, 3, 4, 5, 7, 6, 8, 9]

flatMerge([1,2,3], [3, 2, 1, 5], [7, 6, 8, 9]);
// [1, 2, 3, 5, 7, 6, 8, 9]

flatMerge(1, 3, 5, 7);
// [1, 3, 5, 7]
Array.prototype.pushUnique = function(values)
{
    for (var i=0; i < values.length; i++)
        if (this.indexOf(values[i]) == -1)
            this.push(values[i]);
};

Try:

var array1 = ["Vijendra","Singh"];
var array2 = ["Singh", "Shakya"];
array1.pushUnique(array2);
alert(array1.toString());  // Output: Vijendra,Singh,Shakya