Checking if a string is null

Unity Engine
1

I had always just used “if ( != null)” to check if a string exists and it seems to work fine, but I came across a forum post that said to use string.IsNullOrEmpty(Name) in response to someone who said that checking if a string is equal to null doesn’t work. This was news to me. Anyone know what’s going on with this? As far as I can tell, both methods work fine, although I found that using “if ( )” doesn’t work (even though it works fine for other objects) since it returns a “Cannot implicitly convert type string to bool” error.

I wish I could just use memory, as in assembly language, so I know what’s going on “under the hood”.

2

They are different.

string s1 = "";
string s2 = null;

if (s1 == null)  // false
if (strings.IsNullOrEmpty(s1)) // true

if (s2 == null)  // true
if (strings.IsNullOrEmpty(s2)) // true

So string.IsNullOrEmpty(s1) is a shorthand for

s1 == null || s1 == ""

The comparison to null tells you if the reference in the variable is valid or not (string is a reference type).
The isNullOrEmpty says if the reference is valid AND if there is something in the variable (other than the empty string)
There is a IsNullOrWhiteSpace method when it’s telling you if there is any character in the variable which is not space, tab, enter or other white space.

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