Sum two numbers to zero

JavaScript

Easy

Objective

Write a function that receives an array of numbers, and returns two that equal zero when added together.

Requirements

The function should be called sumTwoNumbers
It will receive a single parameter, which is an array of numbers
It should return two numbers that add up to zero
1. If there are multiple pairs that sum to zero, the function can return any of them
2. If no two numbers add up to zero, the function should return null

Check your solution

Tests

Function name is sumTwoNumbers
sumTwoNumbers([-1,1,2,3])	Expected:	[-1,1]
sumTwoNumbers([1,2,3,4])	Expected:	null

Solution

Here's how I would approach this, but keep in mind there might be other ways to solve this problem.

function sumTwoNumbers(numbers) {
    // This approach uses a Set, they were added in ES^
    // Create a set to store the numbers
    let numSet = new Set();

    // Loop through the numbers
    for (let num of numbers) {
        // Check if the set contains the negative of the current number
        if (numSet.has(-num)) {
            // If it does, return the negative and the positive
            return [-num, num];
        }
        numSet.add(num);
    }

    // Return null if no pair is found
    return null;
}

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