Chapter 12, Problem 13E

Explanation of Solution

Method definition:

//method definition

    public static int indexOf(String source, String target)

    {

      //condition to validate the length of the source string and target string

    if(target.length() > source.length())

    {

        //return -1

        return -1;

    }

    //condition to validate the substring and target  string length

    else if(source.substring(0, target.length()).equals(target)) {

       //return 0

        return 0;

    }

    //else

    else

    {

        //define the position of the sting

        int pos = indexOf(source...