The task is asking me to make from the String, for example “aaligatoor”, output like: “oaligatoar” I found a solution like:
public static String letterReplacement(final String word) {
String o = "o";
String a = "a";
if (word.contains("a") && word.contains("o")) {
return word.replaceFirst("a", "o")
.replaceFirst("(?s)(.*)" + 'o', "$1" + 'a');
} else {
return "Your word does not contain both of 'a' and 'o' letters, sorry...";
}
}
but it looks tricky, maybe someone knows any more understandable ways to solve this? I appreciate your assistance and attention very much.
Answer
Find the first index of the “a” (String.indexOf()) and the last index of “o” (String.lastIndexOf()). If both indexes are > -1 then swap the letters
Something like:
public class StackOverflow {
public static void main(String[] args) {
String data = "aaligatoor";
int firstAindex = data.indexOf("a");
int lastOindex = data.lastIndexOf("o");
if (firstAindex > -1 && lastOindex > -1) {
char[] letters = data.toCharArray();
letters[firstAindex] = 'o';
letters[lastOindex] = 'a';
data = new String(letters);
}
System.out.println(data);
}
}
Result
oaligatoar