Find even odd index digit difference - JavaScript

We are required to write a JavaScript function that takes in a number and returns the difference of the sums of the digits at even place and the digits at odd place.

Understanding the Problem

Given a number, we need to:

• Sum all digits at even positions (0, 2, 4, ...)
• Sum all digits at odd positions (1, 3, 5, ...)
• Return the absolute difference between these sums

Example

For the number 345336:

• Position 0: 6 (even)
• Position 1: 3 (odd)
• Position 2: 3 (even)
• Position 3: 5 (odd)
• Position 4: 4 (even)
• Position 5: 3 (odd)

Even sum: 6 + 3 + 4 = 13
Odd sum: 3 + 5 + 3 = 11
Difference: |13 - 11| = 2

Using Recursive Approach

const num = 345336;
const evenOddDifference = (num, res = 0, ind = 0) => {
    if(num){
        if(ind % 2 === 0){
            res += num % 10;
        }else{
            res -= num % 10;
        }
        return evenOddDifference(Math.floor(num / 10), res, ind + 1);
    }
    return Math.abs(res);
};
console.log(evenOddDifference(num));

2

Using String Conversion Method

const evenOddDifferenceString = (num) => {
    const digits = num.toString().split('').reverse();
    let evenSum = 0;
    let oddSum = 0;
    
    for(let i = 0; i 

2
2


Comparison

Conclusion

Both methods effectively calculate the difference between even and odd positioned digits. The string method is more readable, while the recursive approach demonstrates functional programming concepts.