Why isn't main() returning any value? - c

Question

/I am trying to return the 1st bit of boolean value of 10 using right shift in the cb function./
#include<stdbool.h>
bool cb(int N,int i){ //`called function`
return ((N>>i)&1)==1;
}
int main(void) { //`main function`
cb(10,1);
return 0;
}
//Status:successfully Executed,but no output.

Answer 1

main doesn't magically return the result of another function, you need to return the value also from main
int main(void)
{
return cb(10, 1);
}
or you can exit the program from your function with a value:
bool cb(int N,int i){ //`called function`
exit(((N>>i)&1)==1 ? EXIT_FAILURE : EXIT_SUCCESS);
}
and check the return in the console:
./yourprogram
echo $?
But notice that this is considered bad practice, we usualy return EXIT_FAILURE only when something went wrong, instead, you can print the result:
int main(void)
{
printf("%d\n", cb(10, 1));
return 0;
}
Finaly, you can use a debugger
Change your code to
Line 6 int res = cb(10, 1);
Line 7 return 0;
and start the debugger
gdb yourprogram
breakpoint 7 (after the line you want to inspect)
run
print res

Answer 2

So Here's your program:
#include<stdbool.h>
//`called function`
bool cb(int N,int i)
{
return ((N >> i) & 1) ==1;
}
//`main function`
int main(void)
{
cb(10,1);
return 0;
}
Your program is executing - which means that the main() function is returning successfully (a Value of 0). You also invoke cb(10,1); which calls your function declaration above (and returns a boolean: True/False). But you don't store the value of that function call, nor display the value with a printf() or cout statement.
You'll need to add more for your program to give you more noticable output.