JavaScript: Find the position of a rightmost round number in an array of integers. Returns 0 if there are no round number

JavaScript Basic: Exercise-139 with Solution

Find Position of Rightmost Round Number

Write a JavaScript program to find the position of the rightmost round number in an array of integers. If there are no round numbers, the function returns 0.

Note: A round number is informally considered to be an integer that ends with one or more zeros.

Visual Presentation:

Sample Solution:

JavaScript Code:

/**
 * Function to find the index of the rightmost round number (divisible by 10) in the array
 * @param {number[]} input_arr - The input array of numbers
 * @returns {number} - The index of the rightmost round number (if found)
 */
function find_rightmost_round_number(input_arr) {
  var result = 0; // Variable to store the index of the rightmost round number (default: 0)
  for (var i = 0; i < input_arr.length; i++) {
    if (input_arr[i] % 10 === 0) { // Checking if the number is divisible by 10
      result = i; // Updating 'result' with the current index if the number is divisible by 10
    }
  }
  return result; // Returning the index of the rightmost round number
}

console.log(find_rightmost_round_number([1, 22, 30, 54, 56]));  
console.log(find_rightmost_round_number([1, 22, 32, 54, 56]));  
console.log(find_rightmost_round_number([1, 22, 32, 54, 50]));   

Output:

2
0
4

Live Demo:

See the Pen javascript-basic-exercise-139 by w3resource (@w3resource) on CodePen.

Flowchart:

ES6 Version:

/**
 * Function to find the index of the rightmost round number (divisible by 10) in the array
 * @param {number[]} input_arr - The input array of numbers
 * @returns {number} - The index of the rightmost round number (if found)
 */
const find_rightmost_round_number = (input_arr) => {
  let result = 0; // Variable to store the index of the rightmost round number (default: 0)
  
  for (let i = 0; i < input_arr.length; i++) {
    if (input_arr[i] % 10 === 0) { // Checking if the number is divisible by 10
      result = i; // Updating 'result' with the current index if the number is divisible by 10
    }
  }
  
  return result; // Returning the index of the rightmost round number
}

console.log(find_rightmost_round_number([1, 22, 30, 54, 56]));  
console.log(find_rightmost_round_number([1, 22, 32, 54, 56])); 
console.log(find_rightmost_round_number([1, 22, 32, 54, 50]));

For more Practice: Solve these Related Problems:

• Write a JavaScript program that finds the index of the rightmost round number in an array (a number ending in zero).
• Write a JavaScript function that iterates through an array from the end and returns the position of the first element ending in zero.
• Write a JavaScript program that scans an array for round numbers and outputs the index of the last occurrence, or returns 0 if none are found.

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