javascript - 如何在JavaScript中合并两个数组并删除重复项(How to merge two arrays in JavaScript and de-duplicate items)

Question

I have two JavaScript arrays:

(我有两个JavaScript数组：)

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

I want the output to be:

(我希望输出为：)

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

The output array should have repeated words removed.

(输出数组应删除重复的单词。)

How do I merge two arrays in JavaScript so that I get only the unique items from each array in the same order they were inserted into the original arrays?

(如何在JavaScript中合并两个数组，以使每个数组中的唯一项按插入原始数组中的相同顺序获得？)

  ask by Vijjendra translate from so

Answer 1

To just merge the arrays (without removing duplicates)

(仅合并数组（不删除重复项）)

ES5 version use Array.concat : (ES5版本使用Array.concat ：)

 var array1 = ["Vijendra", "Singh"]; var array2 = ["Singh", "Shakya"]; console.log(array1.concat(array2)); 

ES6 version use destructuring (ES6版本使用解构)

const array1 = ["Vijendra","Singh"];
const array2 = ["Singh", "Shakya"];
const array3 = [...array1, ...array2];

Since there is no 'built in' way to remove duplicates ( ECMA-262 actually has Array.forEach which would be great for this), we have to do it manually:

(由于没有“内置”方式来删除重复项（ ECMA-262实际上具有Array.forEach对此非常Array.forEach ），因此我们必须手动执行此操作：)

Array.prototype.unique = function() {
    var a = this.concat();
    for(var i=0; i<a.length; ++i) {
        for(var j=i+1; j<a.length; ++j) {
            if(a[i] === a[j])
                a.splice(j--, 1);
        }
    }

    return a;
};

Then, to use it:

(然后，使用它：)

var array1 = ["Vijendra","Singh"];
var array2 = ["Singh", "Shakya"];
// Merges both arrays and gets unique items
var array3 = array1.concat(array2).unique(); 

This will also preserve the order of the arrays (ie, no sorting needed).

(这也将保留数组的顺序（即无需排序）。)

Since many people are annoyed about prototype augmentation of Array.prototype and for in loops, here is a less invasive way to use it:

(由于许多人都对Array.prototype原型扩展和for in循环感到烦恼，因此这是一种侵入性较小的使用方式：)

function arrayUnique(array) {
    var a = array.concat();
    for(var i=0; i<a.length; ++i) {
        for(var j=i+1; j<a.length; ++j) {
            if(a[i] === a[j])
                a.splice(j--, 1);
        }
    }

    return a;
}

var array1 = ["Vijendra","Singh"];
var array2 = ["Singh", "Shakya"];
    // Merges both arrays and gets unique items
var array3 = arrayUnique(array1.concat(array2));

For those who are fortunate enough to work with browsers where ES5 is available, you can use Object.defineProperty like this:

(对于那些幸运地使用ES5的浏览器的人，可以使用Object.defineProperty如下所示：)

Object.defineProperty(Array.prototype, 'unique', {
    enumerable: false,
    configurable: false,
    writable: false,
    value: function() {
        var a = this.concat();
        for(var i=0; i<a.length; ++i) {
            for(var j=i+1; j<a.length; ++j) {
                if(a[i] === a[j])
                    a.splice(j--, 1);
            }
        }

        return a;
    }
});