void
hello everyone!
i found a strange thing.
1.i inputed the codes followed in "CodeBlocks",but it returned this "error:'main' must return 'int'".why?
2.but it run smoothly,when writing in this way(just without "void"):Code:#include<stdio.h> void main() { printf("hello world!"); }
3.the two case all can run smoothly in "TC".Code:#include<stdio.h> main() { printf("hello world!"); }
why?
i find the reason in thispage.
say thanks to laserlight,tabstop,adak,nkrao@gmail haha
Last edited by luoyangke; 10-26-2009 at 09:09 AM. Reason: i find the reason
in wich compiler u getting that error? i mean in "TC" or "GCC" ?
Because "TC" doesn't believe in standards. The standard for the C language requires that main return int. (The C standard allows you, but discourages you, to declare a function without a return type and have it default to int.)
Because according to the C standard (or at least its intended interpretation, for a hosted environment like the one you are using, the main function must be defined with a return type of int.Originally Posted by luoyangke
When the return type is not specified, it defaults to int. However, you should not rely on this. (Unfortunately, I was not able to quickly determine if the feature is obsolescent or simply not recommended).
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in codeblocks
a thing named "CodeBlocks" thank you!
thank you
thank you ! but i still don't understand
Turbo C assumes all functions without a return type, return an int, even though you did not specify a return at all.
Conversely, if you did specify a return type, then it will expect you also to specify the return explicitly, at the end of that function. If the function has a return type of void, then it will give you an error if you specify a return type.
so,
Code:main() { //int return is assumed and handled by the compiler - OK } int main() { //int is specified and return is, as well - OK return 0; } but int main() { //int return type specified, but not present. Causes a compiler error }
thank you
thanks
However, third version as quoted above is equivalent to the second version according to the 1999 edition of the C standard (which Turbo C presumably does not support).
You're welcome
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