I need help to do my exercises. I want to replace letters ‘a’ with an ‘e’ in a phrase. For the input: "are you angry" the output should be: "ere you engry". I tried this but I can't fix it.

public static void main (String [] args){
    String s= "are you angry";
    remplaceLettre(s);

}
public static void remplaceLettre(String s){
    char converted = 0;
    String w = "e";
       
    for (int i = 0; i < s.length(); i  ) {
        if (s.charAt(i) =='a') {
            converted = Character.toUpperCase(s.charAt(i));
            w = s.replace(s.charAt(i), converted);
            s = w;
                
        } else {
            converted = Character.toUpperCase(s.charAt(i));
            w = s.replace(s.charAt(i), converted);
            s = w;
        }
    }
    System.out.println(s);
}

}

output : "are you angry"

Expected output : "ere you engry"

CodePudding user response：

You can use String.replace method like this:

public static void remplaceLettre(String s){
   System.out.println(s.replace("a", "e"));
}

If you must use case insensitive replace try this:

s.replaceAll("(?i)a", "e")

CodePudding user response：

    package com.khan.vaquar;

    public class Test {
        public static void main(String[] args) {
            String str = "are you angry";
            char replaceWith = 'e';
            int index[] = { 0, 8 }; //here you can add index want to replace
            replaceLettre(str, replaceWith, index);

        }

        public static String replaceLettre(String str, char ch, int[] index) {
            if (null == str) {
                return str;
            }

            char[] chars = str.toCharArray();
            for (int i = 0; i < index.length; i  ) {
                chars[index[i]] = ch;
            }
            System.out.println(String.valueOf(chars));
            return String.valueOf(chars);
        }

    }

Output : ere you engry