<div>
as far as i understood..<br />
<br />
int i;<br />
....<br />
if (i!=null) // if the variable has been assigned<br />
{<br />
...<br />
}
</div>


as far as i understood..

int i;
....
if (i!=null) // if the variable has been assigned
{
...
}

<div>
The compile errors are:<br />
<br />
with DateTime:<br />
<br />
System.DateTime dt ;<br />
if(dt != null)<br />
...<br />
Operator '!=' cannot be applied to operands of type 'System.DateTime' and '&lt;null&gt;'<br />
<br />
with int:<br />
int i;<br />
if(i==null){i=0;}<br />
...<br />
Operator '==' cannot be applied to operands of type 'int' and '&lt;null&gt;'<br />
<br />

</div>


The compile errors are:

with DateTime:

System.DateTime dt ;
if(dt != null)
...
Operator '!=' cannot be applied to operands of type 'System.DateTime' and '<null>'

with int:
int i;
if(i==null){i=0;}
...
Operator '==' cannot be applied to operands of type 'int' and '<null>'



<div>
<div class="content wysiwyg-content">
System.DateTime d;<br />
<br />
How do you test if the variable d has been assigned?<br />
<br />
What about <br />
<br />
int i;<br />
<br />
?<br />
<br />

</div>
</div>


System.DateTime d;

How do you test if the variable d has been assigned?

What about 

int i;

?



How to test if variable is assigned?

C# is an object-oriented programming language created in conjunction with Microsoft’s .NET framework. Compilation is usually done into the Microsoft Intermediate Language (MSIL), which is then JIT-compiled to native code (and cached) during execution in the Common Language Runtime (CLR).