Question

Is there a recommended way (according to .net Framework guidelines) of checking for null, example:

if (value == null)
{//code1}
else
{//code2}

or

if (value != null)
{//code2}
else
{//code1}

Or the both codes has same performance?

Answer 1

There is no performance difference, so you should strive for improved readability.

For example, it is often a good idea to put the more “regular” path in the if branch, and put the “exceptional” one in the else branch.