What is the Difference between directcast and ctype?
Answer Posted / guest
Ans: The DirectCast keyword introduces a type conversion
operation. You use it the same way you use the CType
keyword, as the following example shows:
Dim Q As Object = 2.37 ' Requires Option Strict to be Off.
Dim I As Integer = CType (Q, Integer) ' Succeeds.
Dim J As Integer = DirectCast (Q, Integer) ' Fails.
Both keywords take an expression to be converted as the
first argument, and the type to convert it to as the second
argument. Both conversions fail if there is no conversion
defined between the data type of the expression and the
data type specified as the second argument.
The difference between the two keywords is that CType
succeeds as long as there is a valid conversion defined
between the expression and the type, whereas DirectCast
requires the run-time type of an object variable to be the
same as the specified type. If the specified type and the
run-time type of the expression are the same, however, the
run-time performance of DirectCast is better than that of
CType.
In the preceding example, the run-time type of Q is Double.
CType succeeds because Double can be converted to Integer,
but DirectCast fails because the run-time type of Q is not
already Integer.
DirectCast throws an InvalidCastException error if the
argument types do not match.
| Is This Answer Correct ? | 4 Yes | 4 No |
Post New Answer View All Answers
What is default method in c#?
What is an arraylist in c#?
Is it possible to force garbage collector to run?
What do you mean by stack and heap in c#?
Is it possible to execute multiple catch block for a single try statement?
How do I calculate relative time?
What is difference between property and variable in c#?
What is the advantage of singleton class?
What is session state in asp net c# with example?
How can I get the ascii code for a character in c#?
Does c# do array bounds checking?
What is the use of console application in c#?
Define constructors
What is nameof c#?
What is enum in c#?