How should I make a function that loops through an array, and checks if any elements are equal
Example:
[a, b, c, d] //false [a, b, a, d] //true
EDIT:
I want to use it with nested arrays, like so:
const a = [[1,2,3],[4,5,6]] //false const b = [[1,2,3],[4,5,1]] //true
EDIT again: I want the nested arrays to be the exact same
const a = [[1,2],[4,5]] //false const b = [[1,2],[1,2]] //true const c = [[1,2][3,4][1,2]] //true
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Answer
You can easily do this using Set
as:
const getResult = (arr) => new Set(arr).size !== arr.length;
You can add all elements to set and then compare size
of set
and length
of arr
.
You will get different length if any element is repeated else same
const arr1 = ['a', 'b', 'c', 'd']; //false const arr2 = ['a', 'b', 'a', 'd']; //true const getResult = (arr) => new Set(arr).size !== arr.length; console.log(getResult(arr1)); console.log(getResult(arr2));
If you want to use nested array then you can flat it before seinding arguments
to getResult
function as:
const a = [ [1, 2, 3], [4, 5, 6], ]; //false const b = [ [1, 2, 3], [4, 5, 1], ]; //true const getResult = (arr) => new Set(arr).size !== arr.length; console.log(getResult(a.flat())); console.log(getResult(b.flat()));