This code replaces all occurrences of the character `'z'` in...

This code replaces all occurrences of the character 'z' in the string S with the character 'p'. Here's how it works step by step:

1. String S = "razzle-dazzle";
   Initializes S with the value "razzle-dazzle".

2. int k;
   Declares an integer variable k.

3. k = S.indexOf("z");
   Finds the index of the first occurrence of the character 'z' in S and assigns it to k. If 'z' is not found, it will assign -1.

4. while(k != -1)
   This loop executes as long as k is not -1 (i.e., there are still occurrences of 'z' in the string).

5. Inside the loop:

   • S = S.substring(0, k) + "p" + S.substring(k+1);
     This replaces the character 'z' at position k with 'p'.

     • S.substring(0, k) gives the part of the string before the 'z'.
     • "p" is added in place of 'z'.
     • S.substring(k+1) gives the part of the string after the 'z'.

   • k = S.indexOf("z");
     Searches for the next occurrence of 'z'.

6. The loop repeats until no more 'z' is found, at which point k becomes -1 and the loop exits.

7. System.out.println(S);
   Prints the modified string.

Output:

The original string "razzle-dazzle" has three occurrences of 'z'. They are replaced by 'p', resulting in:
"rapple-dapple"

This is the output of the program.