Determining sum of array as even or odd in JavaScript

Problem

We are required to write a JavaScript function that takes in an array of integers arr. Our function should return the string 'odd' if the sum of all the elements of the array is odd or 'even' if it's even.

Example

Following is the code ?

const arr = [5, 1, 8, 4, 6, 9];
const assignSum = (arr = []) => {
    const sum = arr.reduce((acc, val) => {
        return acc + val;
    }, 0);
    const isSumEven = sum % 2 === 0;
    return isSumEven ? 'even' : 'odd';
};
console.log(assignSum(arr));

Output

Following is the console output ?

odd

How It Works

The function uses reduce() to calculate the sum of all array elements, then checks if the sum is even using the modulo operator (%). If sum % 2 === 0, the sum is even; otherwise, it's odd.

Alternative Approach Using for Loop

const checkSumParity = (arr) => {
    let sum = 0;
    for (let i = 0; i 

even
odd


Edge Cases

console.log(assignSum([]));        // Empty array
console.log(assignSum([0]));       // Single zero
console.log(assignSum([-2, -3]));  // Negative numbers


even
even
odd


Conclusion
Both approaches effectively determine if an array's sum is even or odd. The reduce() method provides a more functional programming style, while the for loop offers better readability for beginners.