Intialize an data member of class

[lql44]

hi all,
I am trying to initialise an data member of a class, but failed. Any advices?

class MathFunctions
{
public:
	const static double EWMALamda=0.95;
}

Thanks

[z05DSL3A]

class MathFunctions
{
public:
	const static double EWMALamda;
};

double const MathFunctions::EWMALamda=0.95;

See Static members here : http://www.cplusplus.com/doc/tutorial/classes2/