Скачать или смотреть How to Fix the Regexp.Execute Error in VBScript

Learn how to handle errors in VBScript when using the `Regexp.Execute` function by implementing a simple check for matches.
---
This video is based on the question https://stackoverflow.com/q/64975923/ asked by the user 'ukulele' ( https://stackoverflow.com/u/8910535/ ) and on the answer https://stackoverflow.com/a/64976109/ provided by the user '001' ( https://stackoverflow.com/u/669576/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: in vbscript an Error when using Regexp.Execute

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
How to Fix the Regexp.Execute Error in VBScript

Working with regular expressions in VBScript can be a powerful way to search through and manipulate strings. However, you may encounter errors when using the Regexp.Execute function, especially when there are no matches found. In this guide, we will explore the problem and present a straightforward solution to avoid crashes due to these errors.

The Problem: Error on No Match

When executing a regular expression search using Regexp.Execute, many users notice that the script runs smoothly if a match is found. However, if there is no match, VBScript throws an error, causing the program to crash. The scenario looks something like this:

[[See Video to Reveal this Text or Code Snippet]]

In the code above, the regular expression is set to search for "tea1", which is not present in the string "cup of tea". Attempting to access an item from the results when no matches exist will result in an error.

The Solution: Check for Matches

The key to solving this issue is by ensuring that you check if there are any matches before trying to read from the results. Here’s how you can do it:

Execute the Regular Expression: Use the Execute method to get the results.

Check the Count: Before attempting to access the items, check if the count of results is greater than 0.

Handle the Results: If matches are found, process them; otherwise, handle the case with a message indicating no matches.

Implementing the Solution

Here is the updated code that incorporates the necessary checks:

[[See Video to Reveal this Text or Code Snippet]]

Explanation of the Changes

Variable Declaration: The string to be searched remains unchanged.

Regular Expression Setup: The setup for compare_exp stays the same with the pattern we want to search for.

Using a Variable for Results: The results of Execute are stored in a variable (result) to easily check the count.

Conditional Logic: We use an if statement to check if result.count is greater than 0. If it is, we proceed to output the matched value; if not, we inform the user that there was "no match".

Conclusion

By implementing a simple check for matches before trying to access the results of the Regexp.Execute method, you can prevent your VBScript from crashing due to errors. Always remember to validate the presence of matches to ensure smooth execution of your scripts. With this approach, you can confidently work with regular expressions without the fear of unexpected crashes.

Happy scripting!