Question

我有两个名为arr和ar的数组。假设ar有7个元素，arr有6个元素。如果元素在两者中都相同，我想删除一个元素，否则将其分配给一个新变量。到目前为止我有这个：

var arr = new Array(); // Elements are 65,66,67,68,69,70
var newID = new Array();  
var ar = new Array(); // 64,65,66,67,68,69,70

if (ar.length != arr.length) {
                for (var i = 0; i < arr.length; i++) {
                    for (var j = 0; j < ar.length; j++) {
                        if (arr[i] == ar[j]) {
                            delete ar[i];
                            arr.splice(i, 1);
                            break;
                        }
                        newID = ar[i];
                    }
                }
                for (var i = 0; i < ar.length; i++) {
                    newID = ar[i];
                }

这不能正常工作，因为它会与未找到的值进行比较。请帮我纠正。

Answer 1

您可以尝试以下操作：

var arr = [1, 2, 3, 4, 5, 6, 7];
var ar = [2, 4, 6, 8, 10];
var newID = [];

for(var i = 0; i < arr.length; i++){
    for(var j = 0; j < ar.length; j++){
        if(arr[i] == ar[j]){
            newID.push(arr[i]);
            arr.splice(i, 1);
            ar.splice(j, 1);
            break;
        }
    }
}
alert(arr);
alert(ar);
alert(newID);

Answer 2

我会给你以下解决方案。

var ar = [1,2,3,4,5,6,7];
var arr = [3,6,7,8,9,2];

//ES5
var mergedArray = ar.concat(arr);
var newId = [];
for(var i=0;i<mergedArray.length;i++){
    var id = mergedArray[i];
    if(newId.indexOf(id) !== -1) continue;
    newId.push(id);
}
//or smartter
var newId = ar.concat(arr).filter(function(id, pos, self) {
    return self.indexOf(id) === pos;
});
//or ES6
var mergedArray = ar.concat(arr);
var newId = [];
for(let id of mergedArray){
    if(newId.indexOf(id) !== -1) continue;
    newId.push(id);
}
//or smarter ES6
var newId = ar.concat(arr).filter((id, pos, self) => self.indexOf(id) === pos);

选择权在你手中。：）

Answer 3

此处还有一个使用reduce

＆＃13;

var arr1 = [1, 2, 3, 4, 5];
var arr2 = [1, 3, 5, 7, 9];


var result = arr1.reduce(function (prev, value) {

    var isDuplicate = false;
    for (var i = 0; i < arr2.length; i++) {
        if (value == arr2[i]) {
            isDuplicate = true;
            break;
        }
    }
    
    if (!isDuplicate) {
        prev.push(value);
    }
    
    return prev;
    
}, []);


alert(JSON.stringify(result.concat(arr2)));

＆＃13;

<强> EDITED

＆＃13;

var arr1 = [1, 2, 3, 4, 5];
var arr2 = [1, 3, 5, 7, 9];


arr2 = arr2.reduce(function (prev, value) {

    var isDuplicate = false;
    for (var i = 0; i < arr1.length; i++) {
        if (value == arr1[i]) {
            isDuplicate = true;
            break;
        }
    }
      
    if (!isDuplicate) {
        prev.push(value);
    }
       
    return prev;
        
}, []);


alert(JSON.stringify(arr2));

＆＃13;

Answer 4

我只想添加一个js库 - lodash

var _ = require('lodash');

var array1 = [1,2,3,4,5];
var array2 = [3,1,5];

_.difference(array1,array2)
// returns [ 2, 4 ]

Answer 5

var arr = [1, 2,2, 3, 4, 5, 6, 7];

var ar = [2, 4, 6, 8, 10];

var combinearray = [...arr,...ar]

var newArr = new Set(combinearray);

console.log(newArr)

比较两个数组并使用javascript删除相同的值

5 个答案: