I have 2 variables:
object Id = itemType.GetProperty(dataValueField).GetValue(item, null); //=0;
object selectedValue = 0;
And want to compare them.
I have tried:
var a = Id.Equals(selectedValue);
var b = Id == selectedValue;
var c = Object.Equals(Id, selectedValue);
var d = var x = Object.Equals((Object)Id, (Object)selectedValue);
But everything returns false;
Update: Id is typeof Int64? and selectedValue is Int32? but == operator works for Int64? and Int32?
You are comparing the instance and thats why they are different. Do you have to use an object? Could you cast it to an int ?
You could use a custom class and override Equals() and the operator ==.
Take a look at: https://msdn.microsoft.com/en-us/library/ms173147.aspx
I hope it helps.
int Id = itemType.GetProperty(dataValueField).GetValue<int>(item, null);int Id = itemType.GetProperty(dataValueField).GetValue<int>(item, null);I am pretty sure there is a problem with your data types, not the values. If you for example take 0L (long) and an integer with value 0, all ways to check equality return false. If both have the same type (int) for example, it works.
bool x = object.Equals((object)0, (object)0L) returns false. bool x = object.Equals((object)0, (object)0) returns true.Id is typeof Int64? and selectedValue is Int32? but == operator works for Int64? and Int32?
You are right that those types compare properly:
Int64? Id = 0;
Int32? selectedValue = 0;
Console.WriteLine(Id == selectedValue); // indeed true
However, your types are objects, so you have to keep in mind that what actually happens is a comparison of objects:
object IdAsObject = Id;
object selectedValueAsObject = selectedValue;
Console.WriteLine(IdAsObject.Equals(selectedValueAsObject));
Console.WriteLine(IdAsObject == selectedValueAsObject);
Console.WriteLine(Object.Equals(IdAsObject, selectedValueAsObject));
Console.WriteLine(Object.Equals((Object)IdAsObject, (Object)selectedValueAsObject));
And these are all false, since two objects are only equal if they are the same object.
If you want to compare the values, you should make sure to use proper types.
since two objects are only equal if they are the same object. The Equals method has been overridden in Int32 and Int64. The problem here is that the override does a type check first and the type of an Int32 is not the same as an Int64. For now reference, see dotnetframework.org/default.aspx/4@0/4@0/DEVDIV_TFS/Dev10/…. If you want to check it yourself, change both the Id and selectedValue to be an int32 (and cast to object) and do an `idAsObect.Equals(selectedValueAsObject)Have a look at the source code for Int64 and Int32. Excerpt from Int64:
public override bool Equals(Object obj) {
if (!(obj is Int64)) {
return false;
}
return m_value == ((Int64)obj).m_value;
}
If you notice, the first thing the Equals does is a type check. The types are not compatible and your only solution will be to either cast the Int32 to an Int64 or write a custom Equals that does what you need.
And some test to demonstrate:
public class Blah
{
public Int32 Id32 { get; set; }
public Int64 Id64 { get; set; }
}
private void DoTest()
{
var blah = new Blah
{
Id32 = 1,
Id64 = 1
};
object idInt32 = blah.GetType().GetProperty("Id32").GetValue(blah, null);
object idInt64 = blah.GetType().GetProperty("Id64").GetValue(blah, null);
object selectedValue = 1; // default type is Int32
bool areTheSameInt = idInt32.Equals(selectedValue); // true
bool areTheSameLong = idInt64.Equals(selectedValue); // false
}
dataValueField? Can you paste the class foritemTypeand youritem?