What is the difference between bool and Boolean types in C#

What is the difference between bool and Boolean types in C#?

15 Answers

bool is an alias for System.Boolean just as int is an alias for System.Int32. See a full list of aliases here: Built-In Types Table (C# Reference).

I don't believe there is one.

bool is just an alias for System.Boolean

They are one in the same. bool is just an alias for Boolean.

There is no difference - bool is simply an alias of System.Boolean.

(VS.71).aspx

I realise this is many years later but I stumbled across this page from google with the same question.

There is one minor difference on the MSDN page as of now.

VS2005

Note:

If you require a Boolean variable that can also have a value of null, use bool. For more information, see Nullable Types (C# Programming Guide).

VS2010

Note:

If you require a Boolean variable that can also have a value of null, use bool?. For more information, see Nullable Types (C# Programming Guide).

They are the same. Boolean helps simplify conversion back and forth between C# and VB.Net. Most C# programmers tend to prefer 'bool', but if you are in a shop where there's a lot of both VB.Net and C# then you may prefer Boolean because it works in both places.

As has been said, they are the same. There are two because bool is a C# keyword and Boolean a .Net class.

One is an alias for the other.

bool is an alias for the Boolean class. I use the alias when declaring a variable and the class name when calling a method on the class.

They are the same, Bool is just System.Boolean shortened. Use Boolean when you are with a VB.net programmer, since it works with both C# and Vb

bool is a primitive type, meaning that the value (true/false in this case) is stored directly in the variable. Boolean is an object. A variable of type Boolean stores a reference to a Boolean object. The only real difference is storage. An object will always take up more memory than a primitive type, but in reality, changing all your Boolean values to bool isn't going to have any noticeable impact on memory usage.

I was wrong; that's how it works in java with boolean and Boolean. In C#, bool and Boolean are both reference types. Both of them store their value directly in the variable, both of them cannot be null, and both of them require a "convertTO" method to store their values in another type (such as int). It only matters which one you use if you need to call a static function defined within the Boolean class.

Note that Boolean will only work were you have using System; (which is usually, but not necessarily, included) (unless you write it out as System.Boolean). bool does not need using System;

No actual difference unless you get the type string. There when you use reflection or GetType() you get {Name = "Boolean" FullName = "System.Boolean"} for both.

bool is an alias for Boolean. What aliases do is replace one string of text with another (like search/replace-all in notepad++), just before the code is compiled. Using one over the other has no effect at run-time.

In most other languages, one would be a primitive type and the other would be an object type (value type and reference type in C# jargon). C# does not give you the option of choosing between the two. When you want to call a static method defined in the Boolean class, it auto-magically treats Boolean as a reference type. If you create a new Boolean variable, it auto-magically treats it as a reference type (unless you use the Activator.CreateInstance method).

Perhaps bool is a tad "lighter" than Boolean; Interestingly, changing this:

namespace DuckbillServerWebAPI.Models { public class Expense { . . . public bool CanUseOnItems { get; set; } } } 

...to this:

namespace DuckbillServerWebAPI.Models { public class Expense { . . . public Boolean CanUseOnItems { get; set; } } } 

...caused my cs file to sprout a "using System;" Changing the type back to "bool" caused the using clause's hair to turn grey.

(Visual Studio 2010, WebAPI project)