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