Java String Methods (Advanced)

Java provides many built-in methods to work with strings. These methods allow searching, modifying, comparing, trimming, splitting, and formatting string values.

Below are the most commonly used advanced string methods with examples.

1. `charAt()`

Returns a character at a specific index.

2. `substring()`

Extracts a part of the string.

3. `contains()`

Checks whether a string contains a sequence of characters.

4. `startsWith()` and `endsWith()`

5. `replace()` and `replaceAll()`

6. `trim()`

Removes leading and trailing spaces.

7. `split()`

Splits the string into an array.

8. `toCharArray()`

Converts string into an array of characters.

9. `compareTo()`

Compares two strings lexicographically.

10. `format()`

Formats the string like printf.

11. `repeat()` (Java 11+)

Repeats a string multiple times.

12. `isEmpty()` and `isBlank()` (Java 11+)

⭐ Full Example Using Multiple Methods

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

System.out.println("Original: " + text);
System.out.println("Trimmed: " + text.trim());
System.out.println("Upper: " + text.toUpperCase());
System.out.println("Contains 'Java'? " + text.contains("Java"));
System.out.println("Substring: " + text.substring(2, 6));
System.out.println("Char At index 3: " + text.charAt(3));
System.out.println("Repeat: " + text.trim().repeat(2));
}
}

public class Main {

public static void main(String[] args) {

String text = " Java Programming ";

System.out.println("Original: " + text);

System.out.println("Trimmed: " + text.trim());

System.out.println("Upper: " + text.toUpperCase());

System.out.println("Contains 'Java'? " + text.contains("Java"));

System.out.println("Substring: " + text.substring(2, 6));

System.out.println("Char At index 3: " + text.charAt(3));

System.out.println("Repeat: " + text.trim().repeat(2));

}

📌 Summary

Method	Purpose
`charAt(), toCharArray()`	Character access
`substring()`	Extract part of string
`replace(), replaceAll()`	Modify text
`contains(), startsWith(), endsWith()`	Search in strings
`trim(), isEmpty(), isBlank()`	Clean text
`split()`	Break string
`compareTo()`	Compare strings
`format(), repeat()`	Formatting & repetition

Java String Methods (Advanced)