2018-10-10 22:03:03 +00:00
---
id: a5de63ebea8dbee56860f4f2
title: Diff Two Arrays
isRequired: true
challengeType: 5
2019-08-28 13:26:13 +00:00
forumTopicId: 16008
2018-10-10 22:03:03 +00:00
localeTitle: Diff Два массива
---
## Description
2019-08-28 13:26:13 +00:00
< section id = 'description' >
2019-11-20 00:54:48 +00:00
Сравните два массива и верните новый массив с любыми элементами, найденными только в одном из двух заданных массивов, но не обоих. Другими словами, верните симметричную разность двух массивов. Н е забудьте использовать < a href = "https://www.freecodecamp.org/forum/t/how-to-get-help-when-you-are-stuck-coding/19514" target = "_blank" > Read-Search-Ask,< / a > если вы застряли. Попробуйте подключить программу. Напишите свой собственный код. < strong > Заметка< / strong > < br > Вы можете вернуть массив с е г о элементами в любом порядке.
2019-08-28 13:26:13 +00:00
< / section >
2018-10-10 22:03:03 +00:00
## Instructions
2019-08-28 13:26:13 +00:00
< section id = 'instructions' >
2018-10-10 22:03:03 +00:00
< / section >
## Tests
< section id = 'tests' >
```yml
tests:
2019-08-28 13:26:13 +00:00
- text: < code > diffArray([1, 2, 3, 5], [1, 2, 3, 4, 5])</ code > should return an array.
testString: assert(typeof diffArray([1, 2, 3, 5], [1, 2, 3, 4, 5]) === "object");
- text: < code > ["diorite", "andesite", "grass", "dirt", "pink wool", "dead shrub"], ["diorite", "andesite", "grass", "dirt", "dead shrub"]</ code > should return < code > ["pink wool"]</ code > .
testString: assert.sameMembers(diffArray(["diorite", "andesite", "grass", "dirt", "pink wool", "dead shrub"], ["diorite", "andesite", "grass", "dirt", "dead shrub"]), ["pink wool"]);
- text: < code > ["diorite", "andesite", "grass", "dirt", "pink wool", "dead shrub"], ["diorite", "andesite", "grass", "dirt", "dead shrub"]</ code > should return an array with one item.
testString: assert(diffArray(["diorite", "andesite", "grass", "dirt", "pink wool", "dead shrub"], ["diorite", "andesite", "grass", "dirt", "dead shrub"]).length === 1);
- text: < code > ["andesite", "grass", "dirt", "pink wool", "dead shrub"], ["diorite", "andesite", "grass", "dirt", "dead shrub"]</ code > should return < code > ["diorite", "pink wool"]</ code > .
testString: assert.sameMembers(diffArray(["andesite", "grass", "dirt", "pink wool", "dead shrub"], ["diorite", "andesite", "grass", "dirt", "dead shrub"]), ["diorite", "pink wool"]);
- text: < code > ["andesite", "grass", "dirt", "pink wool", "dead shrub"], ["diorite", "andesite", "grass", "dirt", "dead shrub"]</ code > should return an array with two items.
testString: assert(diffArray(["andesite", "grass", "dirt", "pink wool", "dead shrub"], ["diorite", "andesite", "grass", "dirt", "dead shrub"]).length === 2);
- text: < code > ["andesite", "grass", "dirt", "dead shrub"], ["andesite", "grass", "dirt", "dead shrub"]</ code > should return < code > []</ code > .
testString: assert.sameMembers(diffArray(["andesite", "grass", "dirt", "dead shrub"], ["andesite", "grass", "dirt", "dead shrub"]), []);
- text: < code > ["andesite", "grass", "dirt", "dead shrub"], ["andesite", "grass", "dirt", "dead shrub"]</ code > should return an empty array.
testString: assert(diffArray(["andesite", "grass", "dirt", "dead shrub"], ["andesite", "grass", "dirt", "dead shrub"]).length === 0);
- text: < code > [1, 2, 3, 5], [1, 2, 3, 4, 5]</ code > should return < code > [4]</ code > .
testString: assert.sameMembers(diffArray([1, 2, 3, 5], [1, 2, 3, 4, 5]), [4]);
- text: < code > [1, 2, 3, 5], [1, 2, 3, 4, 5]</ code > should return an array with one item.
testString: assert(diffArray([1, 2, 3, 5], [1, 2, 3, 4, 5]).length === 1);
- text: < code > [1, "calf", 3, "piglet"], [1, "calf", 3, 4]</ code > should return < code > ["piglet", 4]</ code > .
testString: assert.sameMembers(diffArray([1, "calf", 3, "piglet"], [1, "calf", 3, 4]), ["piglet", 4]);
- text: < code > [1, "calf", 3, "piglet"], [1, "calf", 3, 4]</ code > should return an array with two items.
testString: assert(diffArray([1, "calf", 3, "piglet"], [1, "calf", 3, 4]).length === 2);
- text: < code > [], ["snuffleupagus", "cookie monster", "elmo"]</ code > should return < code > ["snuffleupagus", "cookie monster", "elmo"]</ code > .
testString: assert.sameMembers(diffArray([], ["snuffleupagus", "cookie monster", "elmo"]), ["snuffleupagus", "cookie monster", "elmo"]);
- text: < code > [], ["snuffleupagus", "cookie monster", "elmo"]</ code > should return an array with three items.
testString: assert(diffArray([], ["snuffleupagus", "cookie monster", "elmo"]).length === 3);
- text: < code > [1, "calf", 3, "piglet"], [7, "filly"]</ code > should return < code > [1, "calf", 3, "piglet", 7, "filly"]</ code > .
testString: assert.sameMembers(diffArray([1, "calf", 3, "piglet"], [7, "filly"]), [1, "calf", 3, "piglet", 7, "filly"]);
- text: < code > [1, "calf", 3, "piglet"], [7, "filly"]</ code > should return an array with six items.
testString: assert(diffArray([1, "calf", 3, "piglet"], [7, "filly"]).length === 6);
2018-10-10 22:03:03 +00:00
```
< / section >
## Challenge Seed
< section id = 'challengeSeed' >
< div id = 'js-seed' >
```js
function diffArray(arr1, arr2) {
var newArr = [];
// Same, same; but different.
return newArr;
}
diffArray([1, 2, 3, 5], [1, 2, 3, 4, 5]);
```
< / div >
< / section >
## Solution
< section id = 'solution' >
```js
2019-08-28 13:26:13 +00:00
function diffArray(arr1, arr2) {
var newArr = [];
var h1 = Object.create(null);
arr1.forEach(function(e) {
h1[e] = e;
});
var h2 = Object.create(null);
arr2.forEach(function(e) {
h2[e] = e;
});
Object.keys(h1).forEach(function(e) {
if (!(e in h2)) newArr.push(h1[e]);
});
Object.keys(h2).forEach(function(e) {
if (!(e in h1)) newArr.push(h2[e]);
});
// Same, same; but different.
return newArr;
}
2018-10-10 22:03:03 +00:00
```
2019-08-28 13:26:13 +00:00
2018-10-10 22:03:03 +00:00
< / section >