Normally, people do casting in the code like this:
Button btnSave = (Button) sender ; |
Where sender is of Object Type
This same casting can be done using the as operator:
Button btnSave = sender as Button; |
There are two advantages to using the ‘as’ operator:
· It makes your code more readable.
· If a type mismatch occurs, the object will become null instead of throwing an exception.
Following is the code sample with which we can test this:
public partial class _Default : System.Web.UI.Page
{
Object obj1 = new Object();
protected void Page_Load(object sender, EventArgs e)
{
obj1 = "String";
}
protected void Button1_Click(object sender, EventArgs e)
{
//This statement will throw an exception
TextBox t1 = (TextBox)obj1;
}
protected void Button2_Click(object sender, EventArgs e)
{
//This will not throw any exception
TextBox t1 = obj1 as TextBox;
}
}
Note: This only works for reference types.
Thanks & Regards,
Arun Manglick
SMTS || Microsoft Technology Practice || Bridgestone - Tyre Link || Persistent Systems || 3023-6258
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