Question

Write a Java program with a method public String replaceChar(String p, int k, char c) { } that given a String p, an int k, and a char c, returns a String with the kth character replaced by c. Of course, 0<=k<=p.length()-1, otherwise raise an exception or error.

Answer 1

//TestCode.java
public class TestCode {
    public String replaceChar(String p, int k, char c) {
        String result = "";
        for (int i = 0; i < p.length(); i++) {
            if (i == k) {
                result += c;
            } else {
                result += p.charAt(i);
            }
        }
        return result;
    }

    public static void main(String[] args) {
        TestCode t = new TestCode();
        System.out.println(t.replaceChar("abcdefgh",2,'z'));
    }
}