js-coding-challenges

Challenge 23: Sum of Array Elements

Write a JavaScript function to sum of all elements in an array.

Write a function called sumArray that takes array in its parameter and returns sum of all array elements.

Answer 1

// Function to sum array elements
function sumArray(array) {
  let sum = 0;

  // Run loop
  for (let i = 0; i < array.length; i++) {
    // Add array element to sum
    sum += array[i]; // sum = sum + array[i];
  }
  return sum;
}

Answer 1 Explanation

The sumArray function takes array as input. Declare sum variable to store sum of all array elements. Run loop for each array element and add array element to sum and finally return sum.

Answer 2 (Array forEach Method)

// Function to sum array elements
function sumArray(array) {
  let sum = 0;

  // Use array forEach method
  array.forEach((element) => {
    // Add element to sum
    sum += element; // sum = sum + element;
  });

  return sum;
}

Answer 2 Explanation

The sumArray function takes array as input. Declare sum variable to store sum of all array elements. Use array forEach() method which run it for each array element and add array element to sum and return sum.

Answer 3 (Array Reduce Method)

// Function to sum array elements
function sumArray(array) {
  // Use array reduce method
  return array.reduce((sum, num) => sum + num, 0);
}

Answer 3 Explanation

The sumArray function takes array as input and it uses the reduce() method to iterate over the array and return the sum of all elements.

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