Class, default constructor ":"

[Vect0rZ]

Hey,

Can you guys explain me a little bit more the : after the default class constructor.
For example

class someClass{
private:
     float x, y;
public:
     someClass(float _x, float _y):
     x     (_x),     y     (_y)
     {};
     ~someClass(){};
};

Thanks in advance =]

[lsk]

It's class member initializer. It's used to assign value to variables in constructor.

someClass(float _x, float _y):x(_x),y(_y){};
is like,

someClass(float _x, float _y){
    x = _x;
    y = _y;
}

[Vect0rZ]

Thank you very much, lsk!=]

[Catfish5]

http://isocpp.org/wiki/faq/ctors#init-lists

[z05DSL3A]

Note: someClass(float _x, float _y) is not a default constructor.
A default constructor is one that takes no arguments.