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What's in it?
RegExpr for VB/VBA is a code module with support
for a full range of regular expressions.
Implemented as pure VB source code, it does not require
any additional run-time libraries.
When do I need it?
If you wish to use regular expressions in Visual Basic 5.0, 6.0 or VBA
as if they were built in the language,
you need RegExpr.
How do I learn them?
We have written a tutorial in the help file.
You may also read the introduction.
Can I just use VB's built-in Like and Replace?
Sure you can - if you're happy with the features they support.
Regular expressions are much more. They can search for all character combinations,
allow "Or" rules, verify the number of character occurrences,
and support zero-width concepts such as word boundaries, end-of-line and "not followed by".
What's good in Aivosto RegExpr?
RegExpr for VB/VBA implements a full range of regular expressions.
It's not a subset such as VB's Like. It doesn't require
any OCXs or DLLs either, to save you from DLL hell.
What are the system requirements?
RegExpr works with Visual Basic 5.0 and 6.0. It also works with Visual Basic for Applications in Word 97 or later, in Excel 95 or later, and in Access 95 or later.
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Introduction to regular expressions
Regular expressions are a pattern matching standard,
somewhat similar to VB's Like statement.
In many programming languages regular expressions are a built-in feature.
RegExpr you add this power to Visual Basic.
Validate user input, search for patterns, parse text, replace strings etc.
What can you do with regular expressions? Examples:
- check if an email address is correctly formed
- parse dates, social security numbers and the like
- extract the 3rd word of a sentence
- find repeated words in a piece of of text
- read;in;semicolon;separated;input
- find all dollar amounts in a string
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Supported expressions
RegExpr supports a wide range of regular expression types.
Here is a short list. The help file has a complete list with instructions.
| x* | Zero or more x's |
| x+ | One or more x's |
| x? | One or zero x's |
| x{m,n} | At least m and at most n x's |
| [A-Z] | Any uppercase character A-Z |
| . | Any single character except a newline |
| \w | Any alphanumeric character |
| \d | Any digit (the same as [0-9]) |
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Advanced syntax
If you already know regexes,
you might be interested in knowing that RegExpr supports almost all possible regexes, such as
| x*? | Stingy or minimal matching |
| $1 $2 ... | Subexpressions or remembered patterns |
| \1 \2 ... | Backreferences |
| (?=text) | Positive lookaheads |
| (?!text) | Negative lookaheads |
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