How can I initialize a sequence in F# with existing items?

Question

In C#, you can initialize a list like so:

var list = new List<int> { obj1, obj2, obj3 };

I was expecting to do something similar in F# but keep getting errors:

let list =  { obj1, obj2, obj3 }

Is this possible in F#?

Answer 1

To create an (immutable) F# list, you can write:

let list = [ obj1; obj2; obj3 ]

There is a number of other options. You can create arrays by using [| .. |] instead of [ .. ] and you can also write sequence expressions that allow you to generate data - similarly to C# iterator methods. For more information, refer to:

• Sequences at F# WikiBook
• Sequences (F#) at MSDN