I am trying to verify whether a variable that is passed can be converted to a specific type. I have tried the following but can\'t get it to compile so I assume I\'m going
I think this is what you're looking for:
var myValue = "42";
int parsedValue;
if (Int32.TryParse(myValue, out parsedValue)) {
// it worked, and parsedValue is equal to 42
}
else {
// it did not work and parsedValue is unmodified
}
EDIT: Just to be clear, the operators is and as are used in the following ways...
The is operator will return a boolean value to indicate whether or not the object being tested either is the type specified or implements the interface specified. It's like asking the compiler "Is my variable this type?":
var someString = "test";
var result = someString is IComparable; // result will be true
The as operator attempts to perform the conversion, and returns a null reference if it can't. This is like telling the compiler "I would like to use this variable as this type":
var someString = "test";
var comparable = someString as IComparable; // comparable will be of type String
If you tried to do this:
var someString = "42";
// using Int32? because the type must be a reference type to be used with as operator
var someIntValue = someString as Int32?;
The compiler will issue an error:
Cannot convert type via a built-in converstion.