Hello Program in Java
Hello Program in Java
The Hello program in Java displays the word Hello on the console. It is the basic program in Java. In this section, we will learn different ways to create and display the word Hello on the console.
Using print() Method
Filename: HelloExample.java
public class HelloExample
{
// Main Method
public static void main(String argvs[])
{
// Displaying the word Hello on the console
System.out.print("Hello");
}
}
Output:
Hello
Explanation: In Java, we use the print() method to print on the console. We have used out object, which is of the class PrintStream, to invoke the print() method. System is the class name.
There are different variations of print() method like println(), printf(). Let us discuss them.
Using println() Method
Filename: HelloExample1.java
public class HelloExample1
{
public static void main(String argvs[])
{
// Displaying the word Hello on the console and
// Forcing the cursor to move to the next line
System.out.println("Hello");
}
}
Output:
Hello
Explanation: Instead of the print() method, we have used the println() method. The extra letters ln, moves the cursor to the next line. Therefore, the following snippet of code
public static void main(String argvs[])
{
System.out.println("Hello");
System.out.println("Hello");
}
Output
Hello Hello
Using printf() Method
Filename: HelloExample2.java
public class HelloExample2
{
public static void main(String argvs[])
{
// Character array
char str[] = {'H', 'e', 'l', 'l', 'o'};
// Loop for displaying the word Hello
for(int i = 0; i < str.length; i++)
{
System.out.printf("%c", str[i]); // Displaying characters
}
}
}
Output:
Hello
Explanation: In the character array, we have stored every character of the word Hello. Then using the Java for-loop, we are iterating over each element of the given character array. In the above-written code, we have used the method printf() to display the word Hello on the console. This method is similar to the printf() function that is used in the C language.
Using Command Line Argument
String argvs[] mentioned as an argument of the main method (main()) is the command-line argument. We can easily pass values to the command-line argument. The following program illustrates the same.
Filename: HelloExample3.java
public class HelloExample3
{
public static void main(String argvs[])
{
// Loop for displaying the strings passed through command-line argument
for(int i = 0; i < argvs.length; i++)
{
System.out.println(argvs[i]); // Displaying Strings
}
}
}
To Compile: javac HelloExample3.java
To Execute: java HelloExample3 Hello
Output:
Hello
Explanation: We can compile the above program using the javac command. During the execution time, we have passed the word Hello as a command-line argument. Finally, we are iterating over the command-line arguments (which is a String array) and displaying the string elements.
By Taking Input From User
Filename: HelloExample4.java
// Importing the class Scanner
import java.util.Scanner;
public class HelloExample4
{
public static void main(String argvs[])
{
Scanner scr = new Scanner(System.in);
String input = scr.nextLine(); // Reading input
System.out.println(input); // Displaying input
}
}
Output:
Hello
Explanation: Using the Scanner class, we are taking input from the user. Then we are displaying the input using the println() method. If the user has input Hello, then the program displays the word Hello on the console.