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

• 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 (0/6 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)}`)