Initializing list

[timothyguo]

Can I write expression in initializing list, for example,

A::A(double diameter):area(diameter*diameter*3.14/4)
{
...
}

here area is a data member of class A.

[firedraco]

Yeah. Just don't try to do something like:

A::A() : diameter(2.5), area(diameter*diameter*3.14/4) //<-- bad, diameter might not be intialized yet
{}

[timothyguo]

thank you very much!
I just read The C++ Primer 4th Ed, and I now know the order of data members is so important.

[mcleano]

Take a look at my article, more importantly Disch's reply: http://www.cplusplus.com/forum/articles/17820/#msg90014