What is significance attached to the main function in C programming?

Answer 1

The main function in C++ is no different to any other function, other than it is the only required function; it defines the entry point of the application. The minimal main function (and therefore the minimal C++ program) is:

#include <stdio.h>

int main()

{

return(0);

}

The main function must always return an integer to the caller (even if not required by the caller). A return value of zero is usually used to indicate the program terminated successfully, however it is up to the programmer to decide what the return value actually means to the caller. It is common to return (-1) upon an unrecoverable error.

Answer 2

In the C Programming language and some of its derivatives, the main() function is the single point of entry into your application. The operating system takes care of loading the program and preparing it for executing, then calls this function to hand over program flow to your application.

Answer 3

Function main() is the application's main routine where a program starts execution.It is the first user-written function run when a program starts.Object-oriented C++ programs consist mostly of classes, but there's always at least one C-like function: main(). main() is called more or less at the beginning of the program's execution, and when main() ends, the runtime system shuts down the program. main() always returns an int, as shown below:

int main() {

// ...Your Code goes here...

}

main() has a special feature: There's an implicit return 0; at the end. Thus if the flow of control simply falls off the end of main(), the value 0 is implicitly returned to the operating system. Most operating systems interpret a return value of 0 to mean "program completed successfully."

main() is the only function that has an implicit return 0; at the end. All other routines that return an int must have an explicit return statement that returns the appropriate int value.

Note that this example shows main() without any parameters. However, main() can optionally declare parameters so that it can access the command line arguments, just as in C.

Answer 4

main() is the entry point for the program. When main() returns, the program ends. The value returned from main() is usually used to denote that the program completed successfully (zero) or that an error has occurred (non-zero). The return value can be collected by another program, script or batch file.

main() is generally used to co-ordinate all the functions in your program, usually within loop, or to simply pass control to another function. For trivial programs, main() may be the only function in your program.

Answer 5

The main function is special because it defines the entry point of the application. As such, main must be declared in the global namespace. Indeed, main is the only function that must be declared in the global namespace; all other functions can be (and indeed should be) declared in any namespace we desire. When we return from main, the program terminates.

Typically, we use the main function to parse any command line switches and pass control to the relevant function(s).

In addition, the main function must always return a value of type int to the execution environment even if we do not explicitly return a value from main. As such, the following is a perfectly valid definition of main in C++ (but not in C):

int main (void) {}

Even if we do not explicitly return a value, the value 0 will be returned anyway (0 typically indicates no error). No other function in C++ behaves like this; if a return value is expected from a function other than main, it must be explicitly returned by that function.

Although some older versions of C allowed us to declare a return value of type void, this is non-standard and is not allowed in C++:

void main (void) {} // valid in some versions of C, but not in C++

Answer 6

The single entry point where every C program starts to execute from