What is the fastest way to check for nullable bool being true in C#?

Question

Wondering if there is a simpler way to check for a nullable bool being true.

I find myself doing code like this a lot which gets real bulky. Any faster way to do it?

bool? x = false;
if (x.hasValue && x.Value) ...

Seems like there must be a clean faster way to check for true

It's not a duplicate because in this question the boolean is a nullable. — , Oct 02 '14 at 13:13
Thank you Hypenate. It's nice that the stackoverflow police has police. — Peter Kellner, Oct 02 '14 at 14:54

Joanvo · Accepted Answer · 2014-10-02T13:59:42.577

16

Use GetValueOrDefault:

if(x.GetValueOrDefault(false))

You can also use this with other types.

edited Oct 02 '14 at 13:59

answered Oct 02 '14 at 12:43

Joanvo

This seems to me like the best solution so I'm checking it. I'd prefer that it not be such a long name and it would be nice if there was someway to say GetValueOrParam1(param1). The way it is now, it seems a little vague because you could easily not know the default value. For example, is default value of string "" or null? Be nice if I could say x.GetValueOrOther("") or something like that. – Peter Kellner Oct 02 '14 at 14:53
Actually, in this function you are passing as parameter the default value *you want* to have when the object has a null value, so in case of string you can choose whatever is convenient to you: an empty string or a null object. – Joanvo Oct 02 '14 at 14:59
Thanks Joanvo, exactly what I wanted. Now, if they could only make it a couple characters instead of a block long method name. – Peter Kellner Oct 02 '14 at 15:56
I guess you can only shorten the function name by creating an extension method of your own which wraps that functionality (+ info: http://msdn.microsoft.com/en-us/library/bb383977.aspx) – Joanvo Oct 03 '14 at 11:08

David Pilkington · Answer 2 · 2014-10-02T12:49:01.527

9

if (x == true)

That should work and is the shortest

edited Oct 02 '14 at 12:49

answered Oct 02 '14 at 12:42

David Pilkington

1

@MXD nope, that wont compile – David Pilkington Oct 02 '14 at 12:44
Did not see the nullable part. My bad. – MX D Oct 02 '14 at 12:46
Surprisingly, it does compile. I wonder what the implication is if it's null? – Peter Kellner Oct 02 '14 at 16:03
@PeterKellner it is evaluated as false – David Pilkington Oct 03 '14 at 04:41
@PeterKellner it does everything `GetValueOrDefault`, just internally so it looks less cluttered. Which is what I thought you were going for – David Pilkington Oct 03 '14 at 04:43

Neel · Answer 3 · 2014-10-02T12:49:42.667

7

May be many developers are not familiar with this but you can use the null coalesce operator (??), as shown below:

    int? x = null;

    // Set y to the value of x if x is NOT null; otherwise, 
    // if x = null, set y to -1. 
    int y = x ?? -1;

and for condition check :-

if (nullableBool ?? false) { ... }

if (nullableBool.GetValueOrDefault(false)) 
{
}

edited Oct 02 '14 at 12:49

answered Oct 02 '14 at 12:43

Neel

What's interesting, the compiler compiles the `??` operator into a call to *GetValueOrDefault*. So, in performance, they are equal; in beauty, the coalesce operator is nicer. ☺ – IS4 Nov 04 '14 at 00:58

3 Answers3