Digit sum upto a number of digits of a number in JavaScript

We are required to write a JavaScript function that takes in two numbers, let’s say m and n as arguments.

n will always be smaller than or equal to the number of digits present in m. The function should calculate and return the sum of first n digits of m.

For example −

If the input numbers are −

const m = 5465767; const n = 4;

Then the output should be −

const output = 20;

because 5 + 4 + 6 + 5 = 20

Example

Following is the code −

const m = 5465767; const n = 4; const digitSumUpto = (m, n) => {    if(n > String(m).length){       return 0;    };    let sum = 0;    for(let i = 0; i < n; i++){       const el = +String(m)[i];       sum += el;    };    return sum; }; console.log(digitSumUpto(m, n));

Output

Following is the console output −

20