Write a function which accepts a string argument and returns the count of characters between the first and last character 'X'.

Instructions

• indexOf and lastIndexOf are the methods on String which returns the position of the given string in the input string from start and end respectively.
• If the match is not found, these methods return -1.

Challenges (0/4 done)

• getTheGapX('XeroX') returns 4.
• getTheGapX('Xamarin') returns 0.
• getTheGapX('JavaScript') returns -1.
• getTheGapX("F(X) !== G(X) !== F(X)") returns 18.

const str = "XeroX";

function getTheGapX(str) {
  // write your solution here

  return;
}

console.log(`Gap between the X's: ${getTheGapX(str)}`);