DEV Community

Funke Olasupo
Funke Olasupo

Posted on

HackerRank Series #1: Simple Array Sum

Problem Statement

Given an array of integers, find the sum of its elements.

For example, if the array $ar = [1,2,3], 1+2+3 =6, so return 6.

Function Description

Complete the simpleArraySum function in the editor below. It must return the sum of the array elements as an integer.

simpleArraySum has the following parameter(s):

ar: an array of integers

Sample Input : 1 2 3 4 10 11
Sample Output : 31
Enter fullscreen mode Exit fullscreen mode


In our text editor on HackerRank, we already have the simpleArraySum() function declared with the parameter $ar which can be any given array. All you need to do is write a set of instructions in the function that will calculate the sum of all array elements so whenever the function is called, it can calculate the sum of the array elements of any simple array.
For example in our Sample Input [1, 2, 3, 4, 10, 11], we expect an output of 31 seeing 1 +2+ 3+ 4 +10 +11 = 31.


Ponder: How do we get all the elements of an arrayπŸ€”? A loop should work fine!😎


Let's try to solve this problem without using codes.

  • Initialize sum to 0.
  • Loop through the array and get the array elements and add the value to sum.
  • At each loop sum is updated with the latest sum value after the previous array element has been added.
  • After the loop, return sum.

Now, let's go coding!

I will be using the for method in Javascript and foreach method in PHP to loop through the array and solve this problem. This isn't static so you can use any valid method to loop through the array in your preferred language.

Now, we can write the Javascript code as follows:

function simpleArraySum(ar) {

   let sum=0;
   for( let i=0;  i<ar.length;  i++ ){
    return sum;
Enter fullscreen mode Exit fullscreen mode

Now, we can write the PHP code as follows:

function simpleArraySum($ar) {

   foreach($ar as $value){
    return $sum;
Enter fullscreen mode Exit fullscreen mode


This would return an output of the sum of the array as a single integer. When using the for method, we are fetching the array elements based on their index so be careful not to do i<=ar.length; in your condition statement. Avoid this common error because an array starts at index [0].

Congratulations!πŸŽ‰πŸŽˆ You completed your first warmup challenge on HackerRank.

P.S: This is the beginning of a series on the warmup algorithm challenges from HackerRank so stay tuned for more amazing challenges.

Top comments (2)

afrndofu profile image

A implementing Higher Order functions reduce function can make it easier
const arr=[1,2,3,4,5]
console.log(arr.reduce((a,b)=>a+b)) // Outputs: 15

prabhukadode profile image

it will solve one test case . But there is another test case which has got arr lenth more than 1000 and for that test case above solution fails .