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constant in C++,

Hi,
I am not able to find out the reason behind below con snippet
Q1.
Class A
{
public:
const int a;
};
how can i initilized it within the class and also from a function outside the calss. because
i am getting an error by writing const int a =12; within the class

===========================
Q2. Class A
{
public:
static int const i =10;
};
this is not throughing any compiler error. But the following code is throwing compiler error
Class A
{
static float const i = 12.0;
};

}
}

phoffric

Q1: > how can i initilized it within the class
You may use a constructor to initialize the constant; e.g., A(int val): a(val) {};

Q1: > how can i initilized it from a function outside the class
Since a is a constant, it is constant at object creation. So you cannot redefine it in a member method.

Q2: > static float const i = 12.0;
Right, it is an error "only static const integral data members can be initialized within a class"
The C++ rule is that integral constant members may be initialized using static const. float is not integral.

I assume you know that "Class" should be "class".

Indivara

For the float version in Q2, you can do this

class A
{
public:
static float const f;
};

const float A::f = 10;

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arijit_rebaca

ASKER

hi phoffric,
I know that it will throw error like ""only static const integral data members can be initialized within a class"
but i want to know the reason????

ASKER CERTIFIED SOLUTION