Dev Nest Guide
javascriptbeginner10 minutes

Sum All Numbers in an Array Using JavaScript

Write a JavaScript function that takes an array of numbers and returns the sum of all the elements. This challenge helps you practice array iteration and basic function usage.

Challenge prompt

Create a function named sumArray that accepts a single argument — an array of numbers. Your function should calculate and return the sum of all numbers in the array. If the array is empty, return 0.

Guidance

  • • Use a loop (for loop or forEach) to iterate over each element in the array.
  • • Initialize a variable to hold the sum before the loop starts.
  • • Add each number in the array to the sum variable inside the loop.
  • • Return the total sum after processing all elements.

Hints

  • • Consider using a for loop to iterate through the array elements.
  • • Remember that the sum variable should start at zero before adding any numbers.
  • • You can also explore the Array.reduce() method for a more concise solution.

Starter code

function sumArray(numbers) {
  // Your code here
}

Expected output

sumArray([1, 2, 3, 4]) returns 10 sumArray([]) returns 0 sumArray([10, -5, 7]) returns 12

Core concepts

arraysloopsfunctionsbasic arithmetic

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