String Method In Java

1.length():
Returns the number of characters in a string.

Program:

String s = "Java";
System.out.println(s.length());

Output:
4

2. charAt():
Returns the character at a specific index.

Program:

String s = "Java";
System.out.println(s.charAt(2));

Output:
v

3. substring():
Extracts a part of the string.
Program:

String s = "Programming";
System.out.println(s.substring(0, 4));

Output:
Prog

4. toUpperCase():
Converts string into uppercase.

Program:

String s = "java";
System.out.println(s.toUpperCase());

Output:
JAVA

5. toLowerCase():
Converts string into lowercase.
Program:

String s = "JAVA";
System.out.println(s.toLowerCase());

Output:
java

6. trim():
Removes spaces from beginning and end.
Program:

String s = " Java ";
System.out.println(s.trim());

Output:
Java

7. equals():
Compares two strings.
Program:

String s1 = "Java";
String s2 = "Java";

System.out.println(s1.equals(s2));

Output:
true

8. equalsIgnoreCase():
Compares strings ignoring uppercase and lowercase.
Program:

String s1 = "java";
String s2 = "JAVA";

System.out.println(s1.equalsIgnoreCase(s2));

Output:
true

9. contains():
Checks whether text exists in string.
Program:

String s = "Hello Java";
System.out.println(s.contains("Java"));

Output:
true

10. startsWith():
Checks starting characters.

Program:

String s = "Java";
System.out.println(s.startsWith("Ja"));

Output:
true

11. endsWith():
Checks ending characters.
Program:

String s = "Java";
System.out.println(s.endsWith("va"));

Output:
true

12. indexOf():
Returns first occurrence index.
Program:

String s = "Java";
System.out.println(s.indexOf('a'));

Output:
1

13. lastIndexOf():
Returns last occurrence index.
Program:

String s = "Java";
System.out.println(s.lastIndexOf('a'));

Output:

3

14. replace():
Replaces characters or words.
Program:

String s = "Java";
System.out.println(s.replace('a', 'o'));

Output:
Jovo

15. concat():
Joins two strings.
Program:

String s1 = "Java";
String s2 = " Programming";

System.out.println(s1.concat(s2));

Output:
Java Programming

16. isEmpty():
Checks whether string is empty.

Program:

String s = "";
System.out.println(s.isEmpty());

Output:

true

17. split():
Splits string into parts.

Program:

String s = "Java,Python,C";

String arr[] = s.split(",");

for(String data : arr) {
    System.out.println(data);
}

Output:

Java
Python
C

18. compareTo():
Compares two strings lexicographically.

System.out.println("Apple".compareTo("Banana"));

Output:

-1

19. valueOf():
Converts other data types into string.

Program:

String s = String.valueOf(100);

System.out.println(s);

Output:
100