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Accumulating array elements to form new array in JavaScript
Problem
We are required to write a JavaScript function that takes in an array of numbers, arr, as the first argument and a number, num, (num <= length of array) as the second argument
Our function should add up each contiguous subarray of length num of the array arr to form corresponding elements of new array and finally return that new array
For example, if the input to the function is −
const arr = [1, 2, 3, 4, 5, 6]; const num = 2;
Then the output should be−
const output = [3, 5, 7, 9, 11];
Output Explanation
Because 1 + 2 = 3, 2 + 3 = 5, and so on...
Example
Following is the code−
const arr = [1, 2, 3, 4, 5, 6];
const num = 2;
const accumulateArray = (arr = [], num = 1) => {
const res = [];
let sum = 0, right = 0, left = 0;
for(; right < num; right++){
sum += arr[right];
};
res.push(sum);
while(right < arr.length){
sum -= arr[left];
sum += arr[right];
right++;
left++;
res.push(sum);
};
return res;
};
console.log(accumulateArray(arr, num));Output
Following is the console output−
[3, 5, 7, 9, 11]
Updated on: 21-Apr-2021
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