Commit 709360c

title: Print an Integer

description: In this program, you'll learn to print a predefined number aw well as a nummber entered by the user in Java.

import { Heading } from '@/components/Heading'

import { List, ListItemGood } from '@/components/List'

import Link from 'next/link'

The integer is stored in a variable using `System.in`, and is displayed on the screen using `System.out`.

To understand this example, you should have the knowledge of the following Java programming topics:

- [Java Hello World Program](/docs/hello-world)

- Java Basic Input and Output

A Java program that prints a number predefined by the user is as follows:

public class HelloWorld {

public static void main(String[] args) {

// assing a variable to store the integer

int number = 10;

// println() prints the following line to the output screen

System.out.println("The number is: " + number);

}

}

```text n

In this program we are printing a constant integer value which is definrd from first.

The integer is stored in an integer variable `number` using the keyword `int` and printed using the keyword `println`.

A Java program that prints a number entered by the user is as follows:

import java.util.Scanner;

public class HelloWorld {

public static void main(String[] args) {

// Creates a reader instance which takes

// input from standard input - keyboard

Scanner reader = new Scanner(System.in);

System.out.print("Enter a number: ");

// nextInt() reads the next integer from the keyboard

int number = reader.nextInt();

// println() prints the following line to the output screen

System.out.println("You entered: " + number);

}

}

```text n

In this program, an object of `Scanner` class, `reader` is created to take inputs from standard input, which is `keyboard`.

Then, `Enter a number` prompt is printed to give the user a visual cue as to what they should do next.

`reader.nextInt()` then reads all entered integers from the keyboard unless it encounters a new line character `\n (Enter)`. The entered integers are then saved to the integer variable `number`.

If you enter any character which is not an integer, the compiler will throw an `InputMismatchException`.

Finally, `number` is printed onto the standard output `(System.out)` - computer screen using the function `println()`.