4.4 KiB
id | title | challengeType | forumTopicId | dashedName |
---|---|---|---|---|
a5de63ebea8dbee56860f4f2 | Diff Two Arrays | 5 | 16008 | diff-two-arrays |
--description--
Compare two arrays and return a new array with any items only found in one of the two given arrays, but not both. In other words, return the symmetric difference of the two arrays.
Note: You can return the array with its elements in any order.
--hints--
diffArray([1, 2, 3, 5], [1, 2, 3, 4, 5])
should return an array.
assert(typeof diffArray([1, 2, 3, 5], [1, 2, 3, 4, 5]) === 'object');
["diorite", "andesite", "grass", "dirt", "pink wool", "dead shrub"], ["diorite", "andesite", "grass", "dirt", "dead shrub"]
should return ["pink wool"]
.
assert.sameMembers(
diffArray(
['diorite', 'andesite', 'grass', 'dirt', 'pink wool', 'dead shrub'],
['diorite', 'andesite', 'grass', 'dirt', 'dead shrub']
),
['pink wool']
);
["diorite", "andesite", "grass", "dirt", "pink wool", "dead shrub"], ["diorite", "andesite", "grass", "dirt", "dead shrub"]
should return an array with one item.
assert(
diffArray(
['diorite', 'andesite', 'grass', 'dirt', 'pink wool', 'dead shrub'],
['diorite', 'andesite', 'grass', 'dirt', 'dead shrub']
).length === 1
);
["andesite", "grass", "dirt", "pink wool", "dead shrub"], ["diorite", "andesite", "grass", "dirt", "dead shrub"]
should return ["diorite", "pink wool"]
.
assert.sameMembers(
diffArray(
['andesite', 'grass', 'dirt', 'pink wool', 'dead shrub'],
['diorite', 'andesite', 'grass', 'dirt', 'dead shrub']
),
['diorite', 'pink wool']
);
["andesite", "grass", "dirt", "pink wool", "dead shrub"], ["diorite", "andesite", "grass", "dirt", "dead shrub"]
should return an array with two items.
assert(
diffArray(
['andesite', 'grass', 'dirt', 'pink wool', 'dead shrub'],
['diorite', 'andesite', 'grass', 'dirt', 'dead shrub']
).length === 2
);
["andesite", "grass", "dirt", "dead shrub"], ["andesite", "grass", "dirt", "dead shrub"]
should return []
.
assert.sameMembers(
diffArray(
['andesite', 'grass', 'dirt', 'dead shrub'],
['andesite', 'grass', 'dirt', 'dead shrub']
),
[]
);
["andesite", "grass", "dirt", "dead shrub"], ["andesite", "grass", "dirt", "dead shrub"]
should return an empty array.
assert(
diffArray(
['andesite', 'grass', 'dirt', 'dead shrub'],
['andesite', 'grass', 'dirt', 'dead shrub']
).length === 0
);
[1, 2, 3, 5], [1, 2, 3, 4, 5]
should return [4]
.
assert.sameMembers(diffArray([1, 2, 3, 5], [1, 2, 3, 4, 5]), [4]);
[1, 2, 3, 5], [1, 2, 3, 4, 5]
should return an array with one item.
assert(diffArray([1, 2, 3, 5], [1, 2, 3, 4, 5]).length === 1);
[1, "calf", 3, "piglet"], [1, "calf", 3, 4]
should return ["piglet", 4]
.
assert.sameMembers(diffArray([1, 'calf', 3, 'piglet'], [1, 'calf', 3, 4]), [
'piglet',
4
]);
[1, "calf", 3, "piglet"], [1, "calf", 3, 4]
should return an array with two items.
assert(diffArray([1, 'calf', 3, 'piglet'], [1, 'calf', 3, 4]).length === 2);
[], ["snuffleupagus", "cookie monster", "elmo"]
should return ["snuffleupagus", "cookie monster", "elmo"]
.
assert.sameMembers(diffArray([], ['snuffleupagus', 'cookie monster', 'elmo']), [
'snuffleupagus',
'cookie monster',
'elmo'
]);
[], ["snuffleupagus", "cookie monster", "elmo"]
should return an array with three items.
assert(diffArray([], ['snuffleupagus', 'cookie monster', 'elmo']).length === 3);
[1, "calf", 3, "piglet"], [7, "filly"]
should return [1, "calf", 3, "piglet", 7, "filly"]
.
assert.sameMembers(diffArray([1, 'calf', 3, 'piglet'], [7, 'filly']), [
1,
'calf',
3,
'piglet',
7,
'filly'
]);
[1, "calf", 3, "piglet"], [7, "filly"]
should return an array with six items.
assert(diffArray([1, 'calf', 3, 'piglet'], [7, 'filly']).length === 6);
--seed--
--seed-contents--
function diffArray(arr1, arr2) {
var newArr = [];
return newArr;
}
diffArray([1, 2, 3, 5], [1, 2, 3, 4, 5]);
--solutions--
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]);
});
return newArr;
}