Test if string begins with a string?

Question

In VBA, what's the most straight forward way to test if a string begins with a substring? Java has startsWith. Is there a VBA equivalent?

Answer 1

There are several ways to do this:

InStr

You can use the InStr build-in function to test if a String contains a substring. InStr will either return the index of the first match, or 0. So you can test if a String begins with a substring by doing the following:

If InStr(1, "Hello World", "Hello W") = 1 Then     MsgBox "Yep, this string begins with Hello W!" End If 

If InStr returns 1, then the String ("Hello World"), begins with the substring ("Hello W").

Like

You can also use the like comparison operator along with some basic pattern matching:

If "Hello World" Like "Hello W*" Then     MsgBox "Yep, this string begins with Hello W!" End If 

In this, we use an asterisk (*) to test if the String begins with our substring.

Answer 2

Judging by the declaration and description of the startsWith Java function, the "most straight forward way" to implement it in VBA would either be with Left:

Public Function startsWith(str As String, prefix As String) As Boolean     startsWith = Left(str, Len(prefix)) = prefix End Function 

Or, if you want to have the offset parameter available, with Mid:

Public Function startsWith(str As String, prefix As String, Optional toffset As Integer = 0) As Boolean     startsWith = Mid(str, toffset + 1, Len(prefix)) = prefix End Function