What is the difference between main function in C java?

Answer 1

// C

int main(int argc, char** argv) {

return 0;

}

// Java

class MainClass {

public static void main(String[] args) {

}

}

Differences:

* Java main method must be in a class; C has no class, so no such requirement exists. * Both accept an array of command-line args. * ** Java arrays know how long they are; C does not and thus the main function must have an additional parameter to know the length of the array. * The Java main method has a specific format; the C main function seems to be allowed to differ. * ** The C main function seems to be able to accept different numbers of arguments and have different return types (assuming the implementation allows it).

Answer 2

The main in Java is the entry point of the program. A Java program starts from main. main is a function. Java is an object oriented language. It means that everything in Java can be called only through objects. But how does a program start? something must be able to create an object isn't it? for this there is main function. Notice the declaration of a main function it will be as :-

public static void main(String[] args) {

}

Here public indicates that the function that you call can be called anywhere from the program(out side the declared classes). static is a keyword which tells that you can directly call a function (in this case main) without creating an object for the function. void tell that the function main doesn't have a return type. In effect public static void main() {}, act as the entry point of the java program.

Remember there will be only one main function in a Java class. Then objects are created inside the main function inside the Java program like

public class Test {

public static void main(String[] args) {

MyClass obj = new MyClass();

obj.myFunction();

}

} // end of Test class

class MyClass {

public void myFunction() {

System.out.println("I am from MyClass");

}

} // end of MyClass

The output of the program would be

I am from MyClass

Answer 3

void main() function just declares a function with return type void..but in java during execution of the program to call the members of a class before an object is created we declare the members as static..so main function must always be declared as static so that it must be called before object is created..and it is declared as public because it can be accesed by code outside the program...main function will not be executed if it is not declared as static in java..

Answer 4

Ideally, a main function in both C and C++ should explicitly return an int to the caller, but in C++ an int with value zero is implicitly returned anyway. And while a main function that returns void is considered an invalid program in C++, this rule isn't strictly enforced in C. Other than that, there is no practical difference.

Generally, a main function in both C and C++ should accept command line arguments and should return an int. The following is a typical signature:

int main(int argc, char* argv)

{

// ...process arguments

return( 0 );

}

The char pointer type may be replaced with a wide-char equivalent (such as wchar_t or unsigned short), depending on whether UNICODE is defined or not, or you may use a TCHAR macro equivalent if available. The first argument, argv[0], is always the fully-qualified path and file name to the program itself, which allows the program to refer to itself even if the user renames the executable. All other arguments in the range argv[1] to argv[argc-1] are those supplied by the caller.

Answer 5

They are the same thing, but in C++, you don't have to use "return 0;" at the end. This feature makes C++ much eaiser to use.