Page 135 - DCAP404 _Object Oriented Programming

Object-oriented Programming

Notes interest (int p, int n, int r = 10);
void cal (void);
};
interest::interest (int p, int n, int r = 10)
{ principal = p; year = n; rate = r;
};
void interest::cal (void)

{
cout<< “Principal” <<principal;
cout << “\ Rate” <<rate;
cout<< “\ Year” <<year;
amount = (float) (p*n*r)/100;
cout<< “\Amount” <<amount;
};

main ( )
{
interest i1(1000,2);
interest i2(1000, 2,15);
clrscr( );
il.cal();
i2.cal();
}

Notes The two objects created and initialized in the main( ) function.

interest i1(1000,2);
interest i2(1000,2, 15);
The data members principal and year of object i1 are initialized to 1000 and 2 respectively at the
time when object i1 is created. The data member rate takes the default value 10 whereas when
the object 12 is created, principal, year and rate are initialized to 1000,2 and 15 respectively.
It is necessary to distinguish between the default
constructor::construct();
and default argument constructor

construct::construct(int = 0)
The default argument constructor can be called with one or no arguments. When it is invoked
with no arguments it becomes a default constructor. But when both these forms are used in a
class, it causes ambiguity for a declaration like construct C1;
The ambiguity is whether to invoke construct: : construct ( ) or construct: : construct (int=O)

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