koobas.hobune.stream
The question is answered, right answer was accepted
Why does if(levelToLoad ==null) not work?
I'm creating a script, here is a snippet,
var levelToLoad : String;
function Start ()
{
if(levelToLoad ==null)
{
Debug.LogError("Have You Forgotten To Fill In levelToLoad?");
}
}
So i want the editor to tell me that i forgot to fill it in if its empty, but this does not work... There is no Debug.LogError even if its empty... Thanks for any information.
As opposed to the other answer you got, string can be null and should be null in C# and other language
It is a safe way to avoid crash while trying to use an non-initialized string.
// Crash
string str;
Console.WriteLine(str);
// No Crash
string str = null;
Console.WriteLine(str);
But a simple declaration does not set the string to null. You need to do it:
var levelToLoad : String = null;
function Start ()
{
if(levelToLoad ==null)
{
Debug.LogError("Have You Forgotten To Fill In levelToLoad?");
}
}
EDIT: I realized Unity does not take comparison (at least not in UnityScript) so you need to use:
if(String.IsNullOrEmpty(levelToLoad))
Even if i add levelToLoad : String = null; this does not work.. I really appreciate you information.
Ok my bad, the simple comparison does not do it in Unity !!!??? You need to use if(String.IsNullOrEmpty(levelToLoad))
IsNullOrEmpty is always the safest way. $$anonymous$$eep in $$anonymous$$d that Unity will initialize public variables automatically in the inspector which would set strings to an empty string and not to null.
A string is a reference type, but it's treated differently by the compiler and usually is never null since it acts more like a value type. You can set it explicitly to null, but the value you assign in field-initializers are overwritten by Unity when the object is deserialized at the beginning.
As general rule: Inspector-value > field-initializer-value.
So no matter what you set in the script, the inspector will overwrite it.
strings aren't supposed to be null--well atleast not in c#. if c# you would do:
if(String.IsNullOrEmpty(levelToLoad))
or
if(levelToLoad == "")
one of those will work.
Okay great! Successfully implemented if(levelToLoad == ""). Thank you for your time :) I also appreciate you explaining that Strings aren't supposed to be null.. Very helpful. Thank you! :)
fafase down below is right about strings being null, its floats and ints that can't be null.
Well, it's even possible to declare a nullable int or float, but yes, usual value types can't be null.
