Java System.exit(0) vs C++ return 0

Java and C++ are languages with different applications and design goals. C++ is an extension of procedural programming language C and Java relies on a Java virtual machine to be secure and highly portable. This leads them to many differences. In this article, we will see the difference between C++ return 0 and Java System.exit(0). Before getting into the differences, let us first understand what each of them actually means.

C++ return 0

• In Standard C++, it is recommended to create a main() function with a return type.
• So, the main() function must return an integer value and this integer value is usually the value that will be passed back to the operating system.

In stdlib.h the macros EXIT_SUCCESS and EXIT_FAILURE are defined like this :

#define EXIT_SUCCESS    0
#define EXIT_FAILURE    1

• return 0 --> successful termination.
• return 1 or any other non-zero value --> unsuccessful termination.
• Returning different values like return 1 or return -1 or any other non-zero value means that program is returning error.

#include <iostream>

using namespace std;

int main()
{
    int num1, num2;
    cin >> num1 >> num2;
    cout << num1 + num2;

    return 0;
}

Input:
54
4


Output:
58

Java System.exit(0)

The first thing to take into consideration is that the main function in java has a return type void.

• In Java, you can't return the exit code, because it's a void function. So, if you want to explicitly specify an exit code, you have to use System.exit() method.
• The java.lang.System.exit() method exits the current program by terminating running Java virtual machine.

Declaration for java.lang.System.exit() method:

public static void exit(int status)
exit(0) -->successful termination.
exit(1) or exit(-1) or any other non-zero value –-> unsuccessful termination.

import java.io.*;

class GFG {
    public static void main (String[] args) {
        System.out.println("GeeksForGeeks");
    }
}

Output:
GeeksforGeeks

Note: The work of both return 0 and System.exit(0) is the same as the difference in the return type of the main() functions.  

The following table describes the differences: