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Sum identical elements within one array in JavaScript
We are required to write a JavaScript function that takes in an array of Numbers.
The array might contain some repeating / duplicate entries within it. Our function should add all the duplicate entries and return the new array thus formed.
Example
The code for this will be −
const arr = [20, 20, 20, 10, 10, 5, 1]; const sumIdentical = (arr = []) => { let map = {}; for (let i = 0; i < arr.length; i++) { let el = arr[i]; map[el] = map[el] ? map[el] + 1 : 1; }; const res = []; for (let count in map) { res.push(map[count] * count); }; return res; }; console.log(sumIdentical(arr));
Output
And the output in the console will be −
[ 1, 5, 20, 60 ]
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