Casting an object to a specified System.Type object

Although this seems like something that should be painfully obvious, the method eludes me...

I need to cast an object to a specific System.Type object. It's more clear in code:

...
int a = 1;
int b = 1;
Compare(a,b,typeof(int));
...
public bool Compare(object intA, object intB, Type type)
{
return (intA == intB); //returns false
}

How do I cast intA and intB to integers without doing so explicitly I need to cast them using the System.Type object, since it is unknown within Compare that these are int types.

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Casting an object to a specified System.Type object

PQSIK
I don't believe that will work because the comparer takes instances of object and if the types passed in are int then they will be boxed, so even if the numerical values are the same, the boxed instances will be different and will never return true.

If you are using .NET 2 you can use the generic Comparer<T> to perform the comparison.

DavidTempeArizona

Rabbi Joseph Gordon wrote:
I don't believe that will work because the comparer takes instances of object and if the types passed in are int then they will be boxed, so even if the numerical values are the same, the boxed instances will be different and will never return true.

Of course that is working; just try it - is just one line Console.WriteLine(((object)1).Equals((object)1));

Michael Creamer

Hi,

The objects that you send as parameter are keeping their types (upon you have objects, if you do typeof you will get the original type). I suggest to follow the microsoft approach, using polimorphism like

public bool Compare (int x, int y) { return x.CompareTo(y) == 0; }
public bool Compare (string x, string y) { return x.CompareTo(y) == 0; }

or use CompareTo directly if it is possible (it will be faster)

Cheers
UnknownScripter
Thanks, these answers were somewhat helpful, but the crux of the question was how to cast an object to a specified Type.

In other words, I have an object objA.
And I have a Type typeObjA which is the Type of objA.

Is there anyway to cast objA to this type

Adamus Turner

Dumitru Sbenghe wrote:
Rabbi Joseph Gordon wrote:
I don't believe that will work because the comparer takes instances of object and if the types passed in are int then they will be boxed, so even if the numerical values are the same, the boxed instances will be different and will never return true.

Of course that is working; just try it - is just one line Console.WriteLine(((object)1).Equals((object)1));

I was looking at his comparer method which used == instead of Object.Equals. Using .Equals returns true, using == does not.

mr_c
Try

public bool Compare(object intA, object intB)
{

return intA.Equals(intB);

}

Try to read a little bit about == operator, Equals, ReferenceEquals; The differences between these when applying to references or value types;

Generics will also help you implement situations similar with this one.
Casting an object to a specified System.Type object

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