Home » Java programming language

Java Compiler command() method with example

Compiler Class command() method: Here, we are going to learn about the command() method of Compiler Class with its syntax and example.
Submitted by Preeti Jain, on December 02, 2019

Compiler Class command() method

  • command() method is available in java.lang package.
  • command() method is used to check the argument type and its fields and perform operations related to the command line.
  • command() method is a static method, it is accessible with the class name and if we try to access the method with the class object then we will not get any error.
  • command() method may throw an exception at the time of performing command-line operations.
    NullPointerException: This exception may throw when the given Object parameter is null exists.


    public static Object command(Object ob);


  • Object ob – represents compiler defined parameter.

Return value:

The return type of this method is Object, it returns compiler–defined value and it includes null value.


// Java program to demonstrate the example 
// of Object command(Object ob) method of Compiler 

public class Parent {
    public static void main(String args[]) {
        // Creating a Parent and Child class object
        Parent p1 = new Parent();
        Parent p2 = new Child();

        // By using getClass() method is to get a Parent class
        Class cl1 = p1.getClass();
        System.out.println("p1.getClass() = " + cl1);

        // By using getClass() method is to get a Child class
        Class cl2 = p2.getClass();
        System.out.println("p2.getClass() = " + cl2);

        //By using command(Object ob) method to compile Child //class
        Object ob = Compiler.command("javac Child");
        System.out.println("ob = " + ob);

class Child extends Parent {
    public void show() {
        System.out.println("We are in Child class: ");


p1.getClass() = class Parent
p2.getClass() = class Child
ob = null

Comments and Discussions

Ad: Are you a blogger? Join our Blogging forum.

Languages: » C » C++ » C++ STL » Java » Data Structure » C#.Net » Android » Kotlin » SQL
Web Technologies: » PHP » Python » JavaScript » CSS » Ajax » Node.js » Web programming/HTML
Solved programs: » C » C++ » DS » Java » C#
Aptitude que. & ans.: » C » C++ » Java » DBMS
Interview que. & ans.: » C » Embedded C » Java » SEO » HR
CS Subjects: » CS Basics » O.S. » Networks » DBMS » Embedded Systems » Cloud Computing
» Machine learning » CS Organizations » Linux » DOS
More: » Articles » Puzzles » News/Updates

© https://www.includehelp.com some rights reserved.