?. ??=

?. ??=

 

• Visual Studio 2022
• .Net 6.0
• Console Application

Person? p1 = null;
Person? p2 = new Person("John", 23);

Console.WriteLine(p1?.Name);
Console.WriteLine(p2?.Name);

Console.WriteLine($"p1 is {(p1 ?? new Person("Bob", 12)).ToString()}");

List<Person> pl = new List<Person>();
(pl ??= new List<Person>()).Add(new Person("Jane", 23));
Console.WriteLine($"{pl.Count} : {pl[0].ToString()}");
(pl ??= new List<Person>()).Add(new Person("Sally", 25));
Console.WriteLine($"{pl.Count} : {pl[1].ToString()}");

Console.ReadKey();

class Person
{
    public string Name { get; set; }
    public int Age { get; set; }

    public Person(string name, int age)
    {
        this.Name = name;
        this.Age = age;
    }

    public override string ToString()
    {
        return $"{Name}, {Age}";
    }
}