Problem in string assignment

Hi,
I am facing a problem in assigning a '0' value to string in header file declaration.

I have a header file A.h

Code:

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//A.h

void show(const string s& = 0,int = 0 );

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but here compiler is giving error as :

Quote:

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error: default argument for parameter of type 'const string&' has type 'int'

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I am using gcc version 4.2.1 . I have also used NULL but the result were same.

Where is the problem ??

Can any body help ??

I think you want to write:

Code:

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void show(const string s& = "", int x = 0);

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A good default value for an empty string is "" or std::string(). The second is better: it is the string's default constructor that creates an empty string.

As a side note, you can technically pass 0 (NULL) to string(const char*) constructor, but it will not work as string expects the pointer to be valid and pointing to a null-terminated char array.

Thanks for help......