C/stdlib.h/exit

exit: causes immediate, normal termination of a program

<source lang="cpp">

//Declaration: void exit(int exit_code);

 #include <stdlib.h>
 #include <stdio.h>
 int main(void)
 {
   char choice;
   do {
     printf("Enter names (E)\n");
     printf("Delete name (D)\n");
     printf("Print (P)\n");
     printf("Quit (Q)\n");
     choice = getchar();
   } while(!strchr("EDPQ", toupper(choice)));
   if(choice=="Q") exit(0);
   return choice;
 }

      </source>