Check if array exists in another array with lodash

Question

Is it possible to check if an array

A=[
  "EMPRESA",
  "CD_MAQ",
  "DT_INI_MAQ"
]

Exists in another array

B=[
  "EMPRESA",
  "CD_MAQ",
  "DT_INI_MAQ",
  "CD_WKC",
  "DT_INI_WKC"
]

I want to check if all entries in array A exists in B

You could just check if the [**intersection**](https://lodash.com/docs/4.16.2#intersection) of the two arrays are of equal length to array A: `var completeIntersect = _.intersection(A, B).length === A.length;` — Tholle, Oct 03 '16 at 13:44

score 45 · Accepted Answer · answered Oct 03 '16 at 13:47

var A=[
  "EMPRESA",
  "CD_MAQ",
  "DT_INI_MAQ"
];

var B=[
  "EMPRESA",
  "CD_MAQ",
  "DT_INI_MAQ",
  "CD_WKC",
  "DT_INI_WKC"
];

if ( _.difference(A,B).length === 0){
  // all A entries are into B
}

<script src="https://cdn.jsdelivr.net/lodash/4.16.2/lodash.min.js"></script>

Just use _.difference

score 10 · Answer 2 · answered Oct 03 '16 at 13:49

You can use the intersection of the 2 arrays, and then compare to the original.

var A=[
  "EMPRESA",
  "CD_MAQ",
  "DT_INI_MAQ"
];

var B=[
  "EMPRESA",
  "CD_MAQ",
  "DT_INI_MAQ",
  "CD_WKC",
  "DT_INI_WKC"
];

console.log(_.isEqual(_.intersection(B,A), A));

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.16.2/lodash.js"></script>

score 5 · Answer 3 · answered Dec 22 '22 at 14:53

5

You don't need lodash in this case. Here's one liner with vanilla JS.

A.every(i => B.includes(i))

answered Dec 22 '22 at 14:53

Yan Takushevich

1,843
2
18
23

Elegant, thanks for sharing. The OP requests a solution using Lodash, so technically this doesn't fit the requirement, but this is an elegant solution that removes the requirement to use Lodash (for the better). – Brock Klein Jan 19 '23 at 12:25

Check if array exists in another array with lodash

3 Answers3