What is println() in Java?

Every beginner in the programming world first encounters the println() function, for example, in the classic “Hello World” program.

The main use of println() in Java is to print messages to the computer screen (console).

Normally, you access it through System.out — a standard output stream.

👉 So when you write:

System.out.println("Hello World");

System.out.println("Hello World");

You’re calling the println() method on the out object of the System class.

System is a final class in the java.lang package, and out is a static variable of the System class. The type of out is PrintStream, and println() belongs to the PrintStream class.

This means that both out and println() are part of the PrintStream type, which is why we can access the println() method through the out variable.

PrintStream has many methods for printing messages, and println() is one of them.

Now, let’s break down the word println() to understand its meaning:

“ln” means “line” — it adds a new line after printing each message.

“print” means printing the message on the screen.

Different Variants of `println()`

You can pass different types of data to the println() method, such as integers, characters, booleans, strings, and more.
The println() method automatically converts all types of data into a String format internally.

You don’t have to worry about the data type — println() will handle it for you!

Type	Example
String	`System.out.println("Hello Aitechray");`
int	`System.out.println(101);`
double	`System.out.println(3.14);`
char	`System.out.println('Z');`
boolean	`System.out.println(true);`
Object	`System.out.println(new Object());`

Example Code

public class PrintExample {
    public static void main(String[] args) {
        System.out.println("Learning Java"); // prints a String
        System.out.println(42);              // prints an int
        System.out.println(3.1415);           // prints a double
        System.out.println('J');              // prints a character
        System.out.println(true);             // prints a boolean
    }
}

public class PrintExample {
    public static void main(String[] args) {
        System.out.println("Learning Java"); // prints a String
        System.out.println(42);              // prints an int
        System.out.println(3.1415);           // prints a double
        System.out.println('J');              // prints a character
        System.out.println(true);             // prints a boolean
    }
}