Regular expression for validating names and surnames
As well as text editors, almost every high-level programming language includes support for regular expressions.In this context "the text" is just a string variable, but the operations available are the same. Note: Unless otherwise specified, regular expressions are case-sensitive.Some characters act as metacharacters inside a character class, but as literals outside of a character class. Some characters act as metacharacters in [bcdfghjklmnpqrstvwxyz][bcdfghjklmnpqrstvwxyz][bcdfghjklmnpqrstvwxyz][bcdfghjklmnpqrstvwxyz][bcdfghjklmnpqrstvwxyz][bcdfghjklmnpqrstvwxyz][bcdfghjklmnpqrstvwxyz][bcdfghjklmnpqrstvwxyz][bcdfghjklmnpqrstvwxyz][bcdfghjklmnpqrstvwxyz]), this is not legal syntax in every implementation.
Some programming languages (Perl, Java Script) even provide dedicated syntax for regular expression operations. There's no length limit, but typically the string is quite short. Regular expressions contain a mixture of literal characters, which just represent themselves, and special characters called metacharacters, which do special things. However, almost all implementations provide a flag to enable case-insensitivity.
Some examples are: The string is actually an extremely tiny computer program, and regular expression syntax is a small, terse, domain-specific programming language. Download a dictionary such as this, unzip it and open it. Another note: It is important to know whether "the text" is a sequence of bytes or a sequence of Unicode characters.
Client side validation has always been a potential headache for front-end programmers.
Embedded blocks with a mixture of imperative Java Script and declarative regex can be a mess.
There are two ideas that enters the scene now: Note that it’s only validation. remove spaces in a credit card number) or even replacing (euro is sent to server, whether the user enters euro or €). However, even though it’s already implemented in many browsers, W3C makes it clear that it’s only a working draft. Yes, you guessed it: Java Script according to ECMA-262 Edition 5.
In case (1) as well as (2), a nice red-green feedback lets the user know if the user entered text is correct. For the moment there’s a note in the document that they are aware of this error: NOTE: This requirement is a willful violation of RFC 5322, which defines a syntax for e-mail addresses that is simultaneously too strict (before the “@” character), too vague (after the “@” character), and too lax (allowing comments, white space characters, and quoted strings in manners unfamiliar to most users) to be of practical use here. This is a major drawback, since the regex support in Java Script is modest (e.g.