Create a Phone Number

Problem Description

You are given an array arr of 10 numbers (each number can be between 0 and 9) as an argument. You have to implement the function createPhoneNumber which will return a string of those numbers in the form of a phone number.

Hint 1: Use a loop to iterate through the array.

Hint 2: Use a variable with initial value as empty string and then concatenate the elements of the array one by one to form a string which can be returned.

Sample Input 1
1, 2, 3, 4, 5, 6, 7, 8, 9, 0

Sample Output 1
1234567890

Explanation
Given arr is 1, 2, 3, 4, 5, 6, 7, 8, 9, 0. Concatenating these we get 1234567890.

Sample Input 2
9, 8, 7, 6, 5, 4, 3, 2, 1, 0

Sample Output 2
9876543210

Explanation
Given arr is 9, 8, 7, 6, 5, 4, 3, 2, 1, 0. Concatenating these we get 9876543210.

6 Step Strategy to solve problems

Use the 6 step strategy to solve any problem

Understand the problem

Design test data/test cases (i.e. input and expected output)

Derive the solution (write pseudo code for the solution)

Test the solution (do a dry run of the pseudo code for the test data and confirm it works)

Write the program/code (using JavaScript here)

Test the code (debug any syntax errors and logical errors)

/**
 * @param {number[]} arr
 * @return {string}
 */


function createPhoneNumber(arr){
  // You only need to implement this function.
}

if (createPhoneNumber([9, 8, 7, 4, 5, 6, 3, 2, 1, 0]) !== "9874563210")
  console.log("Test fails: Expected '9874563210' for input arr = [9, 8, 7, 4, 5, 6, 3, 2, 1, 0]");
else
  console.log("Sample test case for input arr = [9, 8, 7, 4, 5, 6, 3, 2, 1, 0] passed!");

module.exports = createPhoneNumber