Exercise 19: Find Sum of All Even Numbers
Problem Statement
Create a function `sumEven(arr)` that returns sum of all even numbers in array.
Example: sumEven([1, 2, 3, 4, 5]) → 6 (2 + 4)
Sample Output:
sumEven([1, 2, 3, 4, 5]) => 6 sumEven([2, 4, 6]) => 12
Solution
const sumEven = (arr) => {
return arr.filter(n => typeof n === "number" && Number.isFinite(n) && n % 2 === 0)
.reduce((sum, n) => sum + n, 0);
};Explanation
Overall Goal:
- Array me sabhi even numbers ka sum calculate karna.
Line 1: Function header
const sumEven = (arr) => {
Line 2-3: Filter and sum
- Even numbers filter, phir sum.
Real world:
- Data processing: even number sums.
- Calculations: conditional sums.