是否有一种方法可以在JavaScript中返回两个数组之间的差异?
例如:
var a1 = ['a', 'b'];
var a2 = ['a', 'b', 'c', 'd'];
// need ["c", "d"]
是否有一种方法可以在JavaScript中返回两个数组之间的差异?
例如:
var a1 = ['a', 'b'];
var a2 = ['a', 'b', 'c', 'd'];
// need ["c", "d"]
当前回答
如果你有两个对象列表
const people = [{name: 'cesar', age: 23}]
const morePeople = [{name: 'cesar', age: 23}, {name: 'kevin', age: 26}, {name: 'pedro', age: 25}]
let result2 = morePeople.filter(person => people.every(person2 => !person2.name.includes(person.name)))
其他回答
const difference = function (baseArray, arrayToCampare, callback = (a, b) => a!== b) {
if (!(arrayToCampare instanceof Array)) {
return baseArray;
}
return baseArray.filter(baseEl =>
arrayToCampare.every(compareEl => callback(baseEl, compareEl)));
}
使用http://phrogz.net/JS/ArraySetMath.js你可以:
var array1 = ["test1", "test2","test3", "test4"];
var array2 = ["test1", "test2","test3","test4", "test5", "test6"];
var array3 = array2.subtract( array1 );
// ["test5", "test6"]
var array4 = array1.exclusion( array2 );
// ["test5", "test6"]
所选的答案只对了一半。您必须比较数组的两种方式才能得到完整的答案。
const ids_exist = [
'1234',
'5678',
'abcd',
]
const ids_new = [
'1234',
'5678',
'efjk',
'9999',
]
function __uniq_Filter (__array_1, __array_2) {
const one_not_in_two = __array_1.filter(function (obj) {
return __array_2.indexOf(obj) == -1
})
const two_not_in_one = __array_2.filter(function (obj) {
return __array_1.indexOf(obj) == -1
})
return one_not_in_two.concat(two_not_in_one)
}
let uniq_filter = __uniq_Filter(ids_exist, ids_new)
console.log('uniq_filter', uniq_filter) // => [ 'abcd', 'efjk', '9999' ]
Array.prototype.difference = function(e) {
return this.filter(function(i) {return e.indexOf(i) < 0;});
};
eg:-
[1,2,3,4,5,6,7].difference( [3,4,5] );
=> [1, 2, 6 , 7]
这个问题很老了,但仍然是javascript数组减法的热门问题,所以我想添加我正在使用的解决方案。适用于以下情况:
var a1 = [1,2,2,3]
var a2 = [1,2]
//result = [2,3]
下面的方法将产生预期的结果:
function arrayDifference(minuend, subtrahend) {
for (var i = 0; i < minuend.length; i++) {
var j = subtrahend.indexOf(minuend[i])
if (j != -1) {
minuend.splice(i, 1);
subtrahend.splice(j, 1);
}
}
return minuend;
}
需要注意的是,该函数不包括减数中没有被减数的值:
var a1 = [1,2,3]
var a2 = [2,3,4]
//result = [1]