C Language Jump Statements Using return
Example
Returning a value
One commonly used case: returning from main()
#include <stdlib.h> /* for EXIT_xxx macros */
int main(int argc, char ** argv)
{
if (2 < argc)
{
return EXIT_FAILURE; /* The code expects one argument:
leave immediately skipping the rest of the function's code */
}
/* Do stuff. */
return EXIT_SUCCESS;
}
Additional notes:
-
For a function having a return type as
void(not includingvoid *or related types), thereturnstatement should not have any associated expression; i.e, the only allowed return statement would bereturn;. -
For a function having a non-
voidreturn type, thereturnstatement shall not appear without an expression. -
For
main()(and only formain()), an explicitreturnstatement is not required (in C99 or later). If the execution reaches the terminating}, an implicit value of0is returned. Some people think omitting thisreturnis bad practice; others actively suggest leaving it out.
Returning nothing
Returning from a void function
void log(const char * message_to_log)
{
if (NULL == message_to_log)
{
return; /* Nothing to log, go home NOW, skip the logging. */
}
fprintf(stderr, "%s:%d %s\n", __FILE__, _LINE__, message_to_log);
return; /* Optional, as this function does not return a value. */
}
