Default value of bool in C#

The default operator in C# returns the default value for any data type. For the bool type, the default value is false.

When a bool variable is declared without initialization, it automatically gets assigned the default value of false.

Syntax

Following is the syntax for using the default operator with bool −

bool variable = default(bool);

In C# 7.1 and later, you can also use the simplified syntax −

bool variable = default;

Using default(bool) Operator

The following example demonstrates how to get the default value of bool using the default operator −

using System;

public class Demo {
   public static void Main() {
      bool a = default(bool);
      // default for bool
      Console.WriteLine("Default for bool type = " + a);
   }
}

The output of the above code is −

Default for bool type = False

Uninitialized bool Variables

When you declare a bool variable without explicit initialization, it automatically receives the default value −

using System;

public class Demo {
   static bool classLevelBool;  // automatically initialized to false
   
   public static void Main() {
      bool localBool = default;  // C# 7.1+ simplified syntax
      
      Console.WriteLine("Class-level bool: " + classLevelBool);
      Console.WriteLine("Local bool with default: " + localBool);
      Console.WriteLine("Are they equal? " + (classLevelBool == localBool));
   }
}

The output of the above code is −

Class-level bool: False
Local bool with default: False
Are they equal? True

Comparison with Other Types

The following example shows default values for different data types including bool −

using System;

public class DefaultValues {
   public static void Main() {
      bool boolDefault = default(bool);
      int intDefault = default(int);
      string stringDefault = default(string);
      char charDefault = default(char);
      
      Console.WriteLine("bool default: " + boolDefault);
      Console.WriteLine("int default: " + intDefault);
      Console.WriteLine("string default: " + (stringDefault ?? "null"));
      Console.WriteLine("char default: '" + charDefault + "'");
   }
}

The output of the above code is −

bool default: False
int default: 0
string default: null
char default: ' '

Conclusion

The default value of bool in C# is false. You can explicitly get this value using default(bool) or the simplified default syntax in C# 7.1+. All uninitialized bool variables automatically receive this default value.