JavaScript: Subtract elements from one another in an array

JavaScript Math: Exercise-45 with Solution

Write a JavaScript function to subtract elements from an array.

Sample Solution:

JavaScript Code:

// Define a function named subtraction that performs subtraction on an array of numbers.
function subtraction(arr) 
{
  // Check if the input is an array.
  if (Object.prototype.toString.call(arr) === '[object Array]') {
    // Initialize the total variable with the first element of the array.
    var total = arr[0];
    // Check if the first element is a number.
    if (typeof (total) !== 'number') {
      return false;
    }
    // Iterate through the array starting from the second element.
    for (var i = 1, length = arr.length; i < length; i++)
    {
      // Check if the current element is a number.
      if (typeof (arr[i]) === 'number')
      {
        // Subtract the current element from the total.
        total -= arr[i];
      } 
      else 
        return false;
    }
    // Return the result of the subtraction.
    return total;
  } 
  else
    return false;
}

// Output the result of subtracting elements in the array [7, 3, 2, -1] to the console.
console.log(subtraction([7,3, 2,-1]));

Output:

3

Visual Presentation:

Flowchart:

Live Demo:

See the Pen javascript-math-exercise-45 by w3resource (@w3resource) on CodePen.

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