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Deep count of elements of an array using JavaScript
Problem
We are required to write a JavaScript function that takes in a nested array of element and return the deep count of elements present in the array.
Input
const arr = [1, 2, [3, 4, [5]]];
Output
const output = 7;
Because the elements at level 1 are 2, elements at level 2 are 2 and elements at level 3 are 1, Hence the deep count is 7.
Example
Following is the code −
const arr = [1, 2, [3, 4, [5]]];
const deepCount = (arr = []) => {
return arr
.reduce((acc, val) => {
return acc + (Array.isArray(val) ? deepCount(val) : 0);
}, arr.length);
};
console.log(deepCount(arr));Code Explanation
We used the Array.prototype.reduce() method to iterate over the array and if at any iteration we encountered a nested array, we recursively called our function.
Output
7
Updated on: 17-Apr-2021
1K+ Views
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