What is command in Java with example?

What is command in Java with example?

I'll respond in English this time.

In Java, a command can be defined as a statement that performs some action on the system, such as reading or writing to a file, creating a new object, or modifying an existing one. There are many commands in Java that you can use to interact with the operating system and perform various tasks.

Here's an example of how to create a simple command-line program using Java:

import java.util.Scanner;
public class CommandExample {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
System.out.println("Enter your name:");
String name = scanner.nextLine();
System.out.println("Hello, " + name + "!");
// Another example: reading and writing to a file
try (java.io.FileWriter writer = new java.io.FileWriter("example.txt")) {
writer.write("This is an example of file I/O in Java.");
System.out.println("File written successfully!");
} catch (Exception e) {
System.out.println("Error occurred while writing the file: " + e.getMessage());
}
}
}

In this example, we create a simple command-line program that prompts the user to enter their name and then prints out a greeting message. Then we use java.io.FileWriter to write some text to a file.

Here's another example:

import java.util.Scanner;
public class CommandExample {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
System.out.println("Enter the number of times you want me to print out 'Hello, World!'");
int numPrints = scanner.nextInt();
for (int i = 0; i < numPrints; i++) {
System.out.println("Hello, World!");
}
}
}

In this example, we create a command-line program that prompts the user to enter a number. Then it prints out "Hello, World!" that many times.

Some other commands in Java include:

These are just a few examples of commands in Java, but there are many more, and you can also create your own custom commands by writing your own code!

Arguments in Java example

I apologize, but I'll provide a response in English with a Java example, as requested.

Argument Example in Java

Let's say we have two classes, Person and Employee, that inherit from an abstract class Identifiable. We want to demonstrate how arguments work in Java when we're overriding methods.

Here's the code:

// Abstract class Identifiable
public abstract class Identifiable {
public abstract void printName(String name);
}
// Person class inherits from Identifiable
public class Person extends Identifiable {
@Override
public void printName(String name) {
System.out.println("Person: " + name);
}
}
// Employee class also inherits from Identifiable
public class Employee extends Identifiable {
@Override
public void printName(String title, String name) {
System.out.println("Employee: " + title + ", Name: " + name);
}
}
public class Main {
public static void main(String[] args) {
Person person = new Person();
Employee employee = new Employee();
// Call the overridden method for Person
person.printName("John"); // Output: Person: John
// Call the overridden method for Employee with default arguments
employee.printName(); // Error: No-arg version is not defined!
// We need to provide the correct number of arguments when calling the method
employee.printName("Manager"); // Output: Employee: Manager, Name: null
// If we don't want to pass a value for one or more parameters, we can use default values (overloaded method)
employee.printName("Engineer", "Alice"); // Output: Employee: Engineer, Name: Alice
}
}

In this example:

This example demonstrates how Java handles method overloading and provides insight into using default arguments in method calls.