The following code demonstrates ten String Class Methods in Java.

Problem Statement

Create a Java application to demonstrate the working of any Ten String class functions. Also, Write code to extract the surname from the complete name

public class StringFunctionsDemo {
    public static void main(String[] args) {
        // Sample input string
        String fullName = "John Doe";

        // 1. Length of the string
        int length = fullName.length();
        System.out.println("1. Length of the full name: " + length);

        // 2. Convert to uppercase
        String upperCaseFullName = fullName.toUpperCase();
        System.out.println("2. Uppercase: " + upperCaseFullName);

        // 3. Convert to lowercase
        String lowerCaseFullName = fullName.toLowerCase();
        System.out.println("3. Lowercase: " + lowerCaseFullName);

        // 4. Check if it starts with a specific prefix
        boolean startsWithJohn = fullName.startsWith("John");
        System.out.println("4. Starts with 'John': " + startsWithJohn);

        // 5. Check if it ends with a specific suffix
        boolean endsWithDoe = fullName.endsWith("Doe");
        System.out.println("5. Ends with 'Doe': " + endsWithDoe);

        // 6. Replace a substring
        String replacedFullName = fullName.replace("John", "Jane");
        System.out.println("6. Replaced 'John' with 'Jane': " + replacedFullName);

        // 7. Get the character at a specific index
        char firstChar = fullName.charAt(0);
        System.out.println("7. First character: " + firstChar);

        // 8. Split the name into first and last name
        String[] nameParts = fullName.split(" ");
        String firstName = nameParts[0];
        String lastName = nameParts[1];
        System.out.println("8. First Name: " + firstName);
        System.out.println("   Last Name: " + lastName);

        // 9. Check if it contains a specific substring
        boolean containsDoe = fullName.contains("Doe");
        System.out.println("9. Contains 'Doe': " + containsDoe);

        // 10. Extract surname from the full name
        String[] fullNameParts = fullName.split(" ");
        if (fullNameParts.length >= 2) {
            String surname = fullNameParts[1];
            System.out.println("10. Surname: " + surname);
        } else {
            System.out.println("10. Invalid full name format.");

In this Java program, we demonstrate the following string functions.

  1. length(): Gets the length of the string.
  2. toUpperCase(): Converts the string to uppercase.
  3. toLowerCase(): Converts the string to lowercase.
  4. startsWith(): Checks if the string starts with a specific prefix.
  5. endsWith(): Checks if the string ends with a specific suffix.
  6. replace(): Replaces a substring with another substring.
  7. charAt(): Gets the character at a specific index.
  8. split(): Splits the string into substrings using a delimiter.
  9. contains(): Checks if the string contains a specific substring.
  10. Custom code to extract the surname from a full name.

Compile and run this Java program to see the output demonstrating these string functions, including the extraction of the surname from the full name.

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