JavaScript - sum only positive numbers in array

In this article, we would like to show you how to sum only positive numbers in array using JavaScript.

Quick solution:

// ONLINE-RUNNER:browser;

var numbers = [1, 2, 3, -4, -5, -6];

var sum = 0;

for (var i = 0; i < numbers.length; ++i) {
    if (numbers[i] > 0) {
        sum += numbers[i];
    }
}

console.log(sum); // 6

Practical example

In this example, we create a reusable arrow function that checks if a number is positive and sums it up.

// ONLINE-RUNNER:browser;

const sumPositive = (numbers) => {
    let sum = 0;
    for (let i = 0; i < numbers.length; ++i) {
        if (numbers[i] > 0) {
            sum += numbers[i];
        }
    }
    return sum;
};


// Usage example:

const result = sumPositive([1, 2, 3, -4, -5, -6]);

console.log(result); // 6