String

1. What is a String?

A String in Java represents a sequence of characters, like a word or sentence. Unlike primitive types, String is a class, and once created, a String object's content cannot be changed (it is "immutable").

2. Why is it used?

Almost every program deals with text in some way — names, messages, addresses. String is the standard way Java represents and works with this kind of text data.

3. Real-Life Example

Think of a printed name tag. Once printed, you can't directly edit the letters on it — you'd need to print an entirely new tag to show a different name. A Java String behaves the same way; any "change" actually creates a brand-new String.

4. Syntax

java
String text = "Hello, Java!";

5. Example Program

java
public class StringDemo {
    public static void main(String[] args) {
        String name = "Java Learner";
        System.out.println("Welcome, " + name);
    }
}

Output:

Welcome, Java Learner

6. Key Points to Remember

• Strings in Java are immutable — every "modification" actually creates a new String object.
• String can be created using double quotes directly, or with the new String() constructor.
• String comparison should use .equals(), not ==, to compare actual content correctly.