The compiler creates a default construtor only in the following situations:

• When the class’s base class defines the default constructor.
• When the class of member objects defines default constructors.
• When the class has a virtual function.
• When the class has a virtual base class.

So for the following class, the compiler does not create a defalut constructor if you do not define one:

class test{	public:		void show();		void get(int, char*, float);	private:		int h,		char* ch;		float f;};