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?
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
DeDuplicate单个或Merge和DeDupliplicate多个数组输入。示例如下。
使用ES6-设置,用于,销毁
我编写了一个接受多个数组参数的简单函数。与上面的解决方案几乎相同,只是有更实际的用例。此函数不会将重复的值连接到一个数组中,以便在稍后阶段删除它们。
短功能定义(仅9行)
/**
* This function merging only arrays unique values. It does not merges arrays in to array with duplicate values at any stage.
*
* @params ...args Function accept multiple array input (merges them to single array with no duplicates)
* it also can be used to filter duplicates in single array
*/
function arrayDeDuplicate(...args){
let set = new Set(); // init Set object (available as of ES6)
for(let arr of args){ // for of loops through values
arr.map((value) => { // map adds each value to Set object
set.add(value); // set.add method adds only unique values
});
}
return [...set]; // destructuring set object back to array object
// alternativly we culd use: return Array.from(set);
}
使用示例代码笔:
// SCENARIO
let a = [1,2,3,4,5,6];
let b = [4,5,6,7,8,9,10,10,10];
let c = [43,23,1,2,3];
let d = ['a','b','c','d'];
let e = ['b','c','d','e'];
// USEAGE
let uniqueArrayAll = arrayDeDuplicate(a, b, c, d, e);
let uniqueArraySingle = arrayDeDuplicate(b);
// OUTPUT
console.log(uniqueArrayAll); // [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 43, 23, "a", "b", "c", "d", "e"]
console.log(uniqueArraySingle); // [4, 5, 6, 7, 8, 9, 10]
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]
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
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。
只需使用Undercore.js的=>uniq即可实现:
array3 = _.uniq(array1.concat(array2))
console.log(array3)
它将印刷[“Vijendra”、“Singh”、“Shakya”]。