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

Array.prototype.add = function(b){
    var a = this.concat();                // clone current object
    if(!b.push || !b.length) return a;    // if b is not an array, or empty, then return a unchanged
    if(!a.length) return b.concat();      // if original is empty, return b

    // go through all the elements of b
    for(var i = 0; i < b.length; i++){
        // if b's value is not in a, then add it
        if(a.indexOf(b[i]) == -1) a.push(b[i]);
    }
    return a;
}

// Example:
console.log([1,2,3].add([3, 4, 5])); // will output [1, 2, 3, 4, 5]

其他回答

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;
  };

您可以简单地使用ECMAScript 6,

var array1 = ["Vijendra", "Singh"];
var array2 = ["Singh", "Shakya"];
var array3 = [...new Set([...array1 ,...array2])];
console.log(array3); // ["Vijendra", "Singh", "Shakya"];

使用排列运算符串联阵列。使用Set创建一组不同的元素。再次使用排列运算符将集合转换为数组。

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>

Use:

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

您可以合并结果并过滤重复项:

let combinedItems = [];

// items is an Array of arrays: [[1,2,3],[1,5,6],...]    
items.forEach(currItems => {
    if (currItems && currItems.length > 0) {
        combinedItems = combinedItems.concat(currItems);
    }
});

let noDuplicateItems = combinedItems.filter((item, index) => {
    return !combinedItems.includes(item, index + 1);
});