Start of main content## More like this

Checks if the elements of the first array are contained in the second one regardless of order.

- Use a
`for...of`

loop over a`Set`

created from the first array. - Use
`Array.prototype.some()`

to check if all distinct values are contained in the second array. - Use
`Array.prototype.filter()`

to compare the number of occurrences of each distinct value in both arrays. - Return
`false`

if the count of any element is greater in the first array than the second one,`true`

otherwise.

```
const isContainedIn = (a, b) => {
for (const v of new Set(a)) {
if (
!b.some(e => e === v) ||
a.filter(e => e === v).length > b.filter(e => e === v).length
)
return false;
}
return true;
};
```

`isContainedIn([1, 4], [2, 4, 1]); // true`

### Check if arrays have same contents

JavaScript, Array

Checks if two arrays contain the same elements regardless of order.

### Array permutations

JavaScript, Array

Generates all permutations of an array's elements (contains duplicates).

### Check if all array elements are unique based on function

JavaScript, Array

Checks if all elements in an array are unique, based on the provided mapping function.