Using ?? : Nullable « Data Type « C# / CSharp Tutorial






  1. C# / CSharp Tutorial
  2. Data Type
  3. Nullable
using System; 
 
class MainClass { 
  static double myMethod() { 
      Console.WriteLine("In myMethod()."); 
      return 0.0; 
  } 
 
  public static void Main() { 
    double? defaultValue = 1.5; 
    double currentBalance; 
 
    currentBalance = defaultValue ?? myMethod(); 
    Console.WriteLine(currentBalance); 
    
    defaultValue = null; 
    currentBalance = defaultValue ?? myMethod(); 
    Console.WriteLine(currentBalance); 
    
  } 
}

1.5
In myMethod().
0




2.54.Nullable
2.54.1.null unification
2.54.2.Nullable long
2.54.3.Nullable Struct
2.54.4.Nullable Types Access: Explicitly use properties
2.54.5.Nullable Types Access: shortcut syntax
2.54.6.Nullable Types Assignment
2.54.7.Null Coalescing Operator
2.54.8.A nullable type
2.54.9.Use nullable objects in expressions: result contains null, because one operand is null
2.54.10.Assign value to nullable int
2.54.11.Using ??