How to Extract Text Following a Regex Match Using Positive Lookbehind Assertion?

Retrieving Post-Match Text Using Regular Expressions

When working with regular expressions, it's often necessary to extract specific components from a match. In some cases, you may desire to capture only the text that follows after a specific pattern is identified.

Question:

A user seeks guidance in obtaining the text that appears after a regex match, excluding the matched string.

Solution:

Using a Positive Lookbehind Assertion

The solution to this challenge lies in employing a positive lookbehind assertion (?<=). This assertion ensures that a match is made at a position immediately following a specified substring (sentence in this case).

By incorporating this lookbehind assertion into your regular expression, you can effectively isolate the desired text. The following modified regex accomplishes this:

(?<=sentence).*

Explanation:

• (?<=sentence): Positive lookbehind assertion that matches at a position right after "sentence" without including it in the match.
• .*: Matches any character or character sequence following the lookbehind assertion.

Example:

Given the input string:

"Some lame sentence that is awesome"

And the above modified regex, the match result would be:

"that is awesome"

This demonstrates the successful extraction of the text following "sentence," excluding "sentence" itself.

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