String Function

 package StringLearning;

class Display {
    public static void print(String s) {
        System.out.println(s);
    }
}

public class StringFunc {
    public static void main(String[] args) {
        String s = "Java Programming";

        // Display original string
        Display.print(s);
        
        // Converts all characters to lower case
        Display.print("LowerCase: " + s.toLowerCase());

        // Converts all characters to upper case
        Display.print("UpperCase: " + s.toUpperCase());

        // Concatenates the specified string to the end of the original string
        Display.print("Concatenation: " + s.concat(" is easy."));

        // Replaces each occurrence of a character with a new character
        Display.print("Replace 'a' with 'b': " + s.replace('a', 'b'));

        // Replaces each occurrence of a substring with a new substring
        Display.print("Replace 'Java' with 'Python': " + s.replace("Java", "Python"));

        // Removes leading and trailing white spaces
        Display.print("Strip: " + s.strip());

        // Extracts a part of the string from the specified index to the end
        Display.print("Substring from index 5: " + s.substring(5));

        // Extracts a part of the string from the specified start index to the end index
        Display.print("Substring from index 5 to 11: " + s.substring(5, 11));

        // Removes leading and trailing spaces
        Display.print("Trim: " + s.trim());

        // Returns the character at the specified index
        Display.print("Character at index 5: " + s.charAt(5));

        // Returns the length of the string
        Display.print("Length: " + s.length());

        // Returns the index of the first occurrence of the specified character
        Display.print("Index of 'a': " + s.indexOf('a'));

        // Returns the index of the first occurrence of the specified substring
        Display.print("Index of 'Program': " + s.indexOf("Program"));

        // Returns the index of the last occurrence of the specified character
        Display.print("Last index of 'a': " + s.lastIndexOf('a'));

        // Checks if the string contains the specified substring
        Display.print("Contains 'Java': " + s.contains("Java"));

        // Checks if the string starts with the specified prefix
        Display.print("Starts with 'Java': " + s.startsWith("Java"));

        // Checks if the string ends with the specified suffix
        Display.print("Ends with 'Programming': " + s.endsWith("Programming"));

        // Splits the string based on the specified delimiter
        String[] parts = s.split(" ");
        for (String part : parts) {
            Display.print("Part: " + part);
        }

        // Joins multiple strings into one, separated by the specified delimiter
        String joinedString = String.join("-", "Java", "Programming", "is", "fun");
        Display.print("Joined string: " + joinedString);

        // Checks if two strings are exactly the same
        Display.print("Equals 'Java Programming': " + s.equals("Java Programming"));

        // Checks if two strings are the same, ignoring case differences
        Display.print("EqualsIgnoreCase 'java programming': " + s.equalsIgnoreCase("java programming"));

        // Compares two strings lexicographically
        Display.print("CompareTo 'Java Programming': " + s.compareTo("Java Programming"));

        // Compares two strings lexicographically, ignoring case differences
        Display.print("CompareToIgnoreCase 'java programming': " + s.compareToIgnoreCase("java programming"));

        // Converts the string into a character array
        char[] charArray = s.toCharArray();
        Display.print("Char array: ");
        for (char c : charArray) {
            System.out.print(c + " ");
        }
        System.out.println();

        // Returns the string representation of different types of values
        Display.print("Value of boolean true: " + String.valueOf(true));
        Display.print("Value of char 'A': " + String.valueOf('A'));
        Display.print("Value of int 123: " + String.valueOf(123));
        Display.print("Value of double 1.23: " + String.valueOf(1.23));

        // Returns a formatted string using the specified format string and arguments
        String formattedString = String.format("Hello %s, %d!", "World", 2023);
        Display.print("Formatted string: " + formattedString);

        // Repeats the string a specified number of times
        Display.print("Repeat 'Hi' 3 times: " + "Hi ".repeat(3));

        // Checks if the string is empty or contains only white space
        Display.print("Is blank: " + " ".isBlank());

        // Checks if the string is empty
        Display.print("Is empty: " + "".isEmpty());

        // Returns a stream of lines extracted from this string, separated by line terminators
        String multilineString = "Line1\nLine2\nLine3";
        Display.print("Lines in string:");
        multilineString.lines().forEach(Display::print);
    }
}