# JavaScript: Even, odd numbers and their sum in an array

## JavaScript Math: Exercise-94 with Solution

Write a JavaScript program to calculate the sum and count of even and odd numbers in an array.

Test Data:
([1,2,3,4,5,6,7]) -> 3,12, 4,16
([2,3,5,1,2,0,3,4,2,3,4)] -> 6,14, 5,15

Sample Solution:

JavaScript Code:

``````/**
* Function to count the number of even and odd numbers and their sums in an array.
* @param {number[]} nums - The array of numbers to be processed.
* @returns {number[]} - An array containing the count and sum of even and odd numbers, respectively.
*/
function test(nums) {
let even = 0, odd = 0;
nums.forEach(number => {
if (number % 2 === 0)
even++;
else
odd++;
});
return [
even,
nums.reduce((s, v) => (!(v % 2) ? s + v : s), 0),
odd,
nums.reduce((s, v) => (v % 2 ? s + v : s), 0)
];
}

// Test cases
let nums = [1, 2, 3, 4, 5, 6, 7];
console.log("Original array: " + nums);
let result = test(nums);
console.log("Number of even numbers and their sum: " + result[0] + "," + result[1]);
console.log("Number of odd numbers and their sum: " + result[2] + "," + result[3]);

nums = [2, 3, 5, 1, 2, 0, 3, 4, 2, 3, 4];
console.log("Original array: " + nums);
result = test(nums);
console.log("Number of even numbers and their sum: " + result[0] + "," + result[1]);
console.log("Number of odd numbers and their sum: " + result[2] + "," + result[3]);
```
```

Output:

```Original array: 1,2,3,4,5,6,7
Number of even numbers and their sum: 3,12
Number of odd numbers and their sum: 4,16
Original array: 2,3,5,1,2,0,3,4,2,3,4
Number of even numbers and their sum: 6,14
Number of odd numbers and their sum: 5,15
```

Flowchart:

Live Demo:

See the Pen javascript-math-exercise-94 by w3resource (@w3resource) on CodePen.

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