find sum of digits in a number code example

Example 1: Determine the sum of al digits of n

def sum_of_digits(n): 
	sum = 0
	while (n != 0): 
		sum = sum + int(n % 10) 
		n = int(n/10) 
	return sum

Example 2: Write a function digitsum that calculates the digit sum of an integer. The digit sum of an integer is the sum of all its digits.

function digSum(n) {
    let sum = 0;
    let str = n.toString();
    console.log(parseInt(str.substring(0, 1)));
    for (let i = 0; i < str.length; i++) {
        sum += parseInt(str.substring(i,i+1));
        
    }
    return sum;
}