Why are regular expressions so hard?
Density. Regular expressions are dense. This makes them hard to read, but not in proportion to the information they carry. Certainly 100 characters of regular expression syntax is harder to read than 100 consecutive characters of ordinary prose or 100 characters of C code.
Why you shouldn’t use regex to parse HTML?
Regular expressions are a tool that is insufficiently sophisticated to understand the constructs employed by HTML. HTML is not a regular language and hence cannot be parsed by regular expressions. Regex queries are not equipped to break down HTML into its meaningful parts.
Is Regex a good practice?
Yes – regular expressions work very well for input validation. However, often times it’s a very good idea to abstract these things away as much as possible as other methods – or even sometimes special validator objects.
Can we use regular expression on files including HTML files?
Entire HTML parsing is not possible with regular expressions, since it depends on matching the opening and the closing tag which is not possible with regexps.
Should you learn regular expressions?
Regular Expressions, also known as Regex, come in handy in a multitude of text processing scenarios. Regex defines a search pattern using symbols and allows you to find matches within strings. Most text editors also allow you to use Regex in Find and Replace matches in your code. …
Do you like regular expressions?
No, I’m not sure you understand: I really love regular expressions. You may find it a little odd that a hack who grew up using a language with the ain’t keyword would fall so head over heels in love with something as obtuse and arcane as regular expressions. I’m not sure how that works.
Why use regular expressions instead of string functions?
At some point in your development you will need to manipulate strings in more complicated ways that simple string functions can’t provide. Regular expressions are used in almost all programming languages and are considered the de facto standard for string manipulation. Regular expressions can also be used in searches and many other utilities.
How can I Make my regex easier to understand?
A tiny ultra-condensed regex is no longer a virtue. Flip on the IgnorePatternWhitespace option, then use that whitespace to make your regex easier for us human beings to parse and understand.
Is it true that regexes are slow?
And yes, regexes can be extremely extremely slow compared to using simple functions. And not just slow, but the performance of the regex engine can be totally unpredictable when faced with arbitrary (user-supplied) inputs.