String

---

public class CharAt {

public static void main(String[] args) {
    String name = "flevia";

    char firstchar = name.charAt(0);
    char thirdchar = name.charAt(2);

    System.out.println("firstcharcter :" + firstchar);
    System.out.println("thirdcharcter :" + thirdchar);

}

}

public class EqualsinString {

public static void main(String[] args) {
    // TODO Auto-generated method stub
String correctusername = "admin";
String correctpassowrd = "admin123";

String inputusername = "admin";
String inputpassword = "admin123";

if (inputusername.equals(correctusername) && inputpassword.equals(correctpassowrd)) {
    System.out.println("Login Successful. Welcome " + inputusername + "!");
} else {
    System.out.println("Invalid credentials. Access Denied.");
}
}

---

public class Length {

   public static void main(String[] args){
        String name = "Flevia";
        int len = name.length();

        System.out.println("Length of the string: " + len);
    }

}

public class Lowercase {

public static void main(String[] args) {
       // Simulated user inputs
    String name = "FLEVIA";
    String city = "CHENNAI";

    // Convert both to uppercase using toUpperCase()
    String upperName = name.toLowerCase();
    String upperCity = city.toLowerCase();

    // Display standardized output
    System.out.println("Name: " + upperName);
    System.out.println("City : " + upperCity);

}
}

---

public class Replace {
public static void main(String[] args) {
// Original message from user
String message = "This movie is stupid and boring!";

    // Replace bad words using replace()
    message = message.replace("stupid", "****");
    message = message.replace("boring", "*****");

    // Display filtered message
    System.out.println("Filtered Message: " + message);
}

}

public class Substring {

public static void main(String[] args) {
       String date = "2025-07-16";  // Example: real-time input from a user or file

        // Extract parts using substring()
        String year = date.substring(0, 4);    // index 0 to 3
        String month = date.substring(5, 7);   // index 5 to 6
        String day = date.substring(8);        // index 8 to end

        // Print results
        System.out.println("Year: " + year);
        System.out.println("Month: " + month);
        System.out.println("Day: " + day);
    }


}

---

public class Trim {

public static void main(String[] args) {
    // TODO Auto-generated method stub
    String name =" flevia ";
    System.out.println("beforetrim : " + name);

    String trimedname = name.trim();
    System.out.println("trim : " + trimedname);

}

}

---

public class Uppercase {
public static void main(String[] args) {
// Simulated user inputs
String name = "flevia g";
String city = "chennai";

// Convert both to uppercase using toUpperCase()
String upperName = name.toUpperCase();
String upperCity = city.toUpperCase();

// Display standardized output
System.out.println("Name (UPPERCASE): " + upperName);
System.out.println("City (UPPERCASE): " + upperCity);

}
}