Function in C not returning anything when it's supposed to return int [duplicate]

Question

Possible Duplicate:
Function returns value without return statement

what is the return value of the function that returns int, but isn't returning anything explicitly.

For instance output of

 int fun() { printf("\ncrap"); } void main() { printf("\n return value of fun %d", fun()); }

The output I am getting is :

 crap return value of fun 1

Does this depend on compiler I am using ?

Thanks !!!

The answer is whatever's in the eax register, I had to add __asm { mov eax, eax; } at the end of the function in order to get it to compile on VC++2010. To get a value of 1 is strange as I would have thought it would have been the return value from the printf("\ncrap") call, which would have been 5. — James
– James, Commented May 31, 2012 at 1:24

nhahtdh · Accepted Answer · 2012-05-31 01:14:30Z

2

You don't have a return value in fun() function, so the value returned is undefined.

answered May 31, 2012 at 1:14

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Comments

Community · Accepted Answer · 2017-05-23 11:56:29Z

It might be returning whatever's in the EAX register, which is probably unreliable without an explicit return value:

waitingkuo · Accepted Answer · 2012-05-31 02:06:47Z

It depends on compiler. That's my output, for your information

compiler: i686-apple-darwin11-llvm-gcc-4.2

crap return value of fun 0