Optional and named arguments in Visual Basic

Defaults, sugar:=True call sites and ParamArray catch-alls.

Console.WriteLine(Brew(2))
Console.WriteLine(Brew(1, "strong"))
Console.WriteLine(Brew(3, sugar:=True))
Console.WriteLine(Total(4, 8, 15, 16, 23, 42))

Function Brew(cups As Integer,
              Optional strength As String = "medium",
              Optional sugar As Boolean = False) As String
    Dim extra = If(sugar, " with sugar", "")
    Return $"{cups} cups, {strength}{extra}"
End Function

Function Total(ParamArray values() As Integer) As Integer
    Return values.Sum()
End Function

How it works

1. Optional ... = "medium" gives the parameter a default.
2. sugar:=True names the argument so the middle default stands.
3. ParamArray collects any number of arguments into an array.

Keywords and builtins used here

• Boolean
• Brew
• Dim
• End
• False
• Function
• If
• Integer
• Optional
• ParamArray
• Return
• String
• Total
• True

The run, in numbers

Lines

15

Characters to type

454

Tokens

123

Three-star pace

80 tpm

At the three-star pace of 80 tokens a minute, this run takes about 92 seconds.

Type this snippet

Step 2 of 3 in Subs & functions, step 14 of 29 in Language basics.

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