Why is Int32.Equals(Int16) always false?

  • Thread starter Thread starter John Mark Howell
  • Start date Start date
J

John Mark Howell

Why is Int32.Equals(Int16) always false?
The following code:
<code>
Int32 a = 123;
Int16 b = 123;
if (a.Equals(b))
Console.WriteLine("a.Equals(b) is true");
else
Console.WriteLine("a.Equals(b) is false");
if (a == b)
Console.WriteLine("a == b is true");
else
Console.WriteLine("a == b is false");
</code>
will generate the following output:

a.Equals(b) is false
a == b is true


Why?
 
...
Why is Int32.Equals(Int16) always false?
Click to expand...

From the documentation for Int32.Equals:

"true if obj is an instance of Int32 and
equals the value of this instance;
otherwise, false."


Observe "if obj is an instance of Int32", as opposed to the == operator that
only compares by value.


// Bjorn A
 
John said:
Why is Int32.Equals(Int16) always false?
The following code:
<code>
Int32 a = 123;
Int16 b = 123;
if (a.Equals(b))
Console.WriteLine("a.Equals(b) is true");
else
Console.WriteLine("a.Equals(b) is false");
if (a == b)
Console.WriteLine("a == b is true");
else
Console.WriteLine("a == b is false");
</code>
will generate the following output:

a.Equals(b) is false
a == b is true

Why?
Click to expand...

As the help file says, the return value is true if the passed object is
an instance of Int32 and equals the value of this instance; otherwise,
false. You are failing on the first check, your passed object is not an
instance of an Int32.
 
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