What is main method in Java

What is main method in Java

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The main method in Java is the entry point of a Java program. It's the first method that gets executed when you run your Java program. The name "main" is also the default class that contains this method, so it's often referred to as Main.

In Java, the main method has two specific characteristics:

Here's a simple example of what the main method might look like:

public class Main {
public static void main(String[] args) {
// Your code here...
}
}

In this example, Main is the name of the class that contains the main method. The main method takes an array of String objects as its argument, which represents the command-line arguments passed to your program.

The main method is the entry point for several reasons:

When you create a new Java project, many IDEs automatically generate a Main class with a main method. This is because the main method serves as the starting point for executing your program.

In summary, the main method in Java is the entry point of a Java program, making it a crucial part of any Java application. It's where execution starts, used by IDEs, and required for some frameworks.

How to run a Java method in terminal?

Running a Java method from the terminal is a straightforward process that requires some basic understanding of how Java works and what tools are available for compiling, running, and testing Java code.

Here's a step-by-step guide on how to run a Java method from the terminal:

Prerequisites

Step 1: Create a new Java class

In your preferred text editor or IDE, create a new file with a .java extension (e.g., MyJavaClass.java). This will be the main entry point for your Java program. Write your Java code in this file, including the method you want to run.

For example:

public class MyJavaClass {
public static void myMethod() {
System.out.println("Hello, World!");
}
public static void main(String[] args) {
myMethod();
}
}

Step 2: Compile your Java code

To compile your Java code, you'll need to use the javac command from the terminal. This will generate a .class file that contains the bytecode for your program.

Open your terminal and navigate to the directory where your Java source file is located:

cd /path/to/your/java/file

Compile your Java code using the following command:

javac MyJavaClass.java

This will generate a MyJavaClass.class file in the same directory.

Step 3: Run your Java program

To run your Java program, you'll need to use the java command from the terminal. This will execute the bytecode generated by javac.

Run your Java program using the following command:

java MyJavaClass

This will execute the main method in your MyJavaClass, which calls your desired myMethod. You should see the output of this method printed to the console.

Tips and Variations

java MyJavaClass myMethod

Replace myMethod with the name of the method you want to run.

java MyJavaClass [argument1] [argument2]

Replace [argument1] and [argument2] with the actual values you want to pass.

That's it! With these steps, you should be able to run a Java method from the terminal.