I'm just starting out with F# and I can't find the syntax to do object initialization like in C# 3.
I.e. given this:
public class Person {
public DateTime BirthDate { get; set; }
public string Name { get; set; }
}
how do I write the following in F#:
var p = new Person { Name = "John", BirthDate = DateTime.Now };
You can do it like this:
let p = new Person (Name = "John", BirthDate = DateTime.Now)
the answer from CMS is definitely correct. Here is just one addition that may be also helpful. In F#, you often want to write the type just using immutable properties. When using the "object initializer" syntax, the properties have to be mutable. An alternative in F# is to use named arguments, which gives you a similar syntax, but keeps things immutable:
type Person(name:string, ?birthDate) =
member x.Name = name
member x.BirthDate = defaultArg birthDate System.DateTime.MinValue
Now we can write:
let p1 = new Person(name="John", birthDate=DateTime.Now)
let p2 = new Person(name="John")
The code requires you to specify the name, but birthday is an optional argument with some default value.
You can also omit the new keyword and use less verbose syntax:
let p = Person(BirthDate = DateTime.Now, Name = "John")
https://learn.microsoft.com/en-us/dotnet/fsharp/language-reference/members/constructors
