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Subject:
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Some confusion in these code
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Posted By:
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hpatel_it
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Post Date:
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8/30/2006 8:19:35 AM
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Hi,
I have read out one sample online article about Interface & Abstract Class. In that article all are mentioned in good way and easily understandable but I have a problem in understanding following code.
Article Link :
http://www.codeproject.com/csharp/A...SInterfaces.asp
In Following code, Lines which are marked by RED color its not understandablel by me.
In short , in first function why we need to use Casting and while in second function why we dont need to use casting.
Can you please help me out for this ?
Code :
private void InterfaceExample_Click(object sender,
System.EventArgs e)
{
try
{
IEmployee emp;
Emp_fulltime2 emp1 = new Emp_fulltime2();
//has to be casted because of the interface!
emp = (IEmployee) emp1;
emp.ID = "2234";
emp.FirstName= "Rahman" ;
emp.LastName = "Mahmoodi" ;
//call add method od the object
MessageBox.Show(emp.Add().ToString());
//call the CalculateWage method
MessageBox.Show(emp.CalculateWage().ToString());
}
catch(Exception ex)
{
MessageBox.Show(ex.Message);
}
}
private void cmdAbstractExample_Click(object sender,
System.EventArgs e)
{
Employee emp;
//no casting is requird!
emp = new Emp_Fulltime();
emp.ID = "2244";
emp.FirstName= "Maria" ;
emp.LastName = "Robinlius" ;
MessageBox.Show(emp.Add().ToString());
//call the CalculateWage method
MessageBox.Show(emp.CalculateWage().ToString());
}
Thanks,
Hiren Patel
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