const char * functionName() const ????

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Original post by GekkoCube
I need a refresher on this.

What exactly does this mean again?

the const char* mean the pointer returned by the function is constant, so the pointer will always point to an address.

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No, it means that the pointer, which is non-constant and can be assigned to, points to constant data.

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1) But what does the const mean after the function name?

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For a member function, const after the function header means that the function will not modify the object.

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2) And since the returned pointer is a const char*, how can i manipulate the data the pointer is pointing to (like an array of char's)?

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You can't; see above. Note: A constant pointer to non-constant characters is a char* const; a constant pointer to constant characters is a const char* const.


[edited by - Miserable on May 4, 2004 11:47:37 PM]

ok first of all thanks.

this is surprising to me because i have broken those rules without the compiler complaining about it.
i had the following:

/// in header file.
const unsigned char * getData() const;

And this is how i used this function:

 unsigned char* pData = (unsigned char*)getData();

 in size = 8;

 for (int i=0; i<size; i++)
 {
   pData += 50; 
 }

1) it suprised me that i cant manipulate the data by adding 50 to each element.

2) and i was surprised that i could typecast the returned type to (unsigned char*) which effectively made the const unsigned char* no longer constant!

you use a c-style cast. they can do anything (nearly).

in the end, it will map to a const_cast => yes, you casted away the constness.

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