Show the Java code for a recursive method int count String t

Show the Java code for a recursive method int count; (String text, char ch) that returns the number of times the character ch appears. For example, count (\"Goodbye\", \' o\') would return 2. You will need to do this recursively by getting a character (first or last) from the string, recursively calling the count () method on the String without the chosen character, and (if the chosen character is equal to ch), add one to the result of the count() on the shorter string. [No points will be given for a solution that uses a loop.] b. Show the java code for a method public static int arraySum(int[] a) that uses recursion to compute the sum of all values in an integer array.)

Solution

Hi, Please find my working implementation.

Please let me know in case of any issue.

public int count(String text, char c){

       // if text is null

       if(text == null)

           return 0;

       // if test has only one character

       if(text.length() == 1){

           if(text.charAt(0) == c)

               return 1;

           else

               return 0;

       }

      

       // if current character is equal to c then add 1 and call for remaining character

       if(text.charAt(0) == c)

           return (1 + count(text.substring(1), c));

       else

           return count(text.substring(1), c);

   }

  

   public static int arraySum(int[] a){

       // base case

       if(a == null)

           return 0;

      

       // if array has only one element

       if(a.length == 1)

           return a[0];

      

       return a[0] + arraySum(Arrays.copyOfRange(a, 1, a.length));

   }