Default parameters in a function

[user name]

Hi,

I just wondered whether you should define the default parameter in the function prototype or the actual function declaration:

int foo(int bar = 0);

...

int foo(int bar)
{
// code
}

OR

int foo(int bar);

...

int foo(int bar = 0)
{
// code
}

(If I put it in both, I get a compile error from g++)

Also, while I'm here, can you tell me whether I should put variable names in the function prototype or just its type:

int foo(int,int,char*);
// OR
int foo(int num, int x, char* text);

Thanks in advance!

[seymore15074]

I like to see default parameters in header files. That way, when you see a function used such as foo() you can look in the header file to see what overloaded functions are available. The header file is where the interface should be; the user of the class/function would want to know the default parameters up front.

[seymore15074]

For the variable names, I also like them in the header file...rather than adding block comments that explain functions, sometimes aptly named parameters can provide enough insight.

[jsmith]

You have to specify the defaults in the header.

[user name]

Oh OK then, thanks!

[user name]

More questions :)

Would this work, or do I have to assign beforehand?

...

if((a=foo.length())==5)    // assign the length of foo to 'a' and compare that to 5 all in one go
    // do stuff

...

If I should've started a new thread then please tell me.

[Bazzy]

Yes, that should work

[user name]

OK, thanks.