How to exit program execution in C++? - c++

Question

Which function is used in C++ stdlib to exit from program execution with status code?
In Java, there's:
System.exit(0)

Answer 1

Assuming you only have one thread:
#include <iostream>
int main()
{
std::cout << "Hello, World!\n";
return(0);
// PROGRAM ENDS HERE.
std::cout << "You should not see this.\n";
return(0);
}
Output:
Hello, World!
The return(0); can be placed anywhere you like - it'll end int main(), and hence your program.
Alternatively, you can call exit(EXIT_SUCCESS); or exit(EXIT_FAILURE); from anywhere you like:
/* exit example */
#include <stdio.h>
#include <stdlib.h>
int main ()
{
FILE * pFile;
pFile = fopen("myfile.txt", "r");
if(pFile == NULL)
{
printf("Error opening file");
exit (1);
}
else
{
/* file operations here */
}
return 0;
}

Answer 2

In addition to the other responses you can also invoke abort, terminate, quick_exit (exits without calling destructors, deallocating etc; hence the name)
terminate calls abort by default but can call any terminate handler you set.
Example usage of abort and set_terminate (to se the handler used by terminate), quick_exit can be called (see example #2)
// set_terminate example
#include <iostream> // std::cerr
#include <exception> // std::set_terminate
#include <cstdlib> // std::abort
void myterminate () {
std::cerr << "terminate handler called\n";
abort(); // forces abnormal termination
}
int main (void) {
std::set_terminate (myterminate);
throw 0; // unhandled exception: calls terminate handler
return 0;
}
quick_exit/at_quick_exit example:
/* at_quick_exit example */
#include <stdio.h> /* puts */
#include <stdlib.h> /* at_quick_exit, quick_exit, EXIT_SUCCESS */
void fnQExit (void)
{
puts ("Quick exit function.");
}
int main ()
{
at_quick_exit (fnQExit);
puts ("Main function: Beginning");
quick_exit (EXIT_SUCCESS);
puts ("Main function: End"); // never executed
return 0;
}
I'm not entirely certain why one would call quick_exit but it exists and thus I should provide documentation for it (courtesy of http://www.cplusplus.com/reference )
Additionally one can call at_exit as the equivalent of at_quick_exit.
Admittedly I am not all that familiar with set_terminate and terminate as I don't call them myself, but I would guess you could use quick_exit as a terminate handler if you wanted; or a custom one (but please don't quote me on that).

Answer 3

In C++, you can use exit(0)
for example:
switch(option){
case 1:
//statement
break;
case 2:
//statement
exit(0);