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constant member functions of a class

Hi, what is the different between the following two ways to use const
in a function definition:

1. const Array &operator=(cons t Array &);
2. int getSize() const;

keyword const to the left of return type and to the right of the
parameter list, what is the different here? I know for the 2nd case,
the function can not modify the object's data member.

Thanks a lot


Jul 23 '05 #1
3 1502

"blueblueblue20 05" <zh******@gmail .com> wrote in message
Hi, what is the different between the following two ways to use const
in a function definition:
These are not function definitions; they are declarations.

1. const Array &operator=(cons t Array &);
The assignment operator takes a reference to const Array object and returns
a reference to const Array object too.
2. int getSize() const;

getSize takes no parameters and returns an int. It promises to not mutate
the object on which this member function has been called.

Jul 23 '05 #2
blueblueblue200 5 wrote:
Hi, what is the different between the following two ways to use const
in a function definition:
Both below statements are function declarations and not definitions.
Definition is when you write code in the function.

1. const Array &operator=(cons t Array &); Function returns a ref to a constant array.
2. int getSize() const; If declared inside a class this means it cannot modify the values of
the class data members. I guess this can be over-ridden if you decl a
data member as mutable. Not sure though.

keyword const to the left of return type and to the right of the
parameter list, what is the different here? I know for the 2nd case,
the function can not modify the object's data member.

Thanks a lot


Jul 23 '05 #3
they are declarations, sorry for the confusion, I just saved typing the
body of the function definition. and they are the member function of a
class. Thanks a lot, now I know the difference, one can not modify the
object itself, the other one can modify the object, but return a const

Jul 23 '05 #4

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