C#•16mo ago

Implement string properties

1, public string Prop { get; set} = string.Empty; 2, public string Prop { get; set} = ""; 3, public string Prop { get; set} = default!; Hi, I am a newbie, could some one help me to have better understand use case of those 3 way implement string properties above ? ( especially 3rd way) Thanks in advanced!

13 Replies

vdvman1•16mo ago

The first two are equivalent, they use an empty string as the default value The last makes it null instead of an empty string, and since you're using ! it looks like you are using nullable reference types, and since you're storing null into a property that states it isn't null you are potentially going to cause issues If you wanted to allow Prop to have a null value, use string? instead of string, and then you can remove the !

TigerThePleb•16mo ago

Is 3rd way is wrong way or could have some design intended?

Henkypenky•16mo ago

the default value is null for reference types it's redundant this

public string Prop { get; set; }

public string Prop { get; set; }

and this

public string Prop { get; set} = default!;

public string Prop { get; set} = default!;

are both null they are the same

MODiX•16mo ago

Henkypenky#4865

REPL Result: Success

Test test = new();

Console.WriteLine(test.Prop1 is null);
Console.WriteLine(test.Prop2 is null);

class Test
{
    public string Prop1 { get; set; }
    public string Prop2 { get; set; } = default!;
}

Test test = new();

Console.WriteLine(test.Prop1 is null);
Console.WriteLine(test.Prop2 is null);

class Test
{
    public string Prop1 { get; set; }
    public string Prop2 { get; set; } = default!;
}

Console Output

True
True

True
True

Compile: 644.741ms | Execution: 96.305ms | React with ❌ to remove this embed.

Henkypenky•16mo ago

C# always had nulls but now you get more help to deal with them in your case if you don't use the null forgiving ! it will shout at you

Henkypenky•16mo ago

this means in a NON NRT world

TigerThePleb•16mo ago

so it's just for bypass waring right?

Henkypenky•16mo ago

when an instance is created it must contain a value, because the default constructor will initialize as null but in NRT world if you mark it as nullable it doesn't matter the compiler knows you said: hey this can be null, chill out yes, it's called the null forgiving operator I highly discourage you from using it

TigerThePleb•16mo ago

yeah im across some internet code sample, just want get a better understand of it

vdvman1•16mo ago

Whether you use: - string and string.Empty - string? and null - string and the required keyword - string and initialise it in the constructor Depends on what values you want the property to hold and how you want it to be set the first time

TigerThePleb•16mo ago

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Henkypenky•16mo ago

Bogus is really god good

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Implement string properties