Generics and tuples in Visual Basic

(Of T) type parameters, constraints and named tuple fields.

Console.WriteLine(Largest({3, 141, 59}))
Console.WriteLine(Largest({"fig", "plum", "apricot"}))

Dim pairs As New List(Of (name As String, score As Integer))
pairs.Add(("ada", 99))
pairs.Add(("alan", 87))
Console.WriteLine($"{pairs(0).name} tops {pairs(1).name}")

Function Largest(Of T As IComparable(Of T))(items As IEnumerable(Of T)) As T
    Dim best = items.First()
    For Each item In items
        If item.CompareTo(best) > 0 Then best = item
    Next
    Return best
End Function

How it works

1. (Of T As IComparable(Of T)) constrains T to things that compare.
2. One Largest serves Integers and Strings alike — inference picks T.
3. (name As String, score As Integer) tuples read by field name.

Keywords and builtins used here

• Dim
• Each
• End
• For
• Function
• If
• Integer
• Largest
• New
• Next
• Of
• Return
• String
• Then

The run, in numbers

Lines

15

Characters to type

464

Tokens

141

Three-star pace

75 tpm

At the three-star pace of 75 tokens a minute, this run takes about 113 seconds.

Type this snippet

Step 3 of 3 in Value types, step 21 of 29 in Language basics.

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