John Davidson

Message:

I'm struggling to find a regular expression that matches a name that can contain a space in it. So far this is what I've tried:

^(?![\s]+$)(?![\s]{2,})[a-zA-Z\s]{2,25}$

Unfortunately I'm not so good on regex. The name can contain only letters and optionally a space character, and if a space is present there must be no more than one space character in the word. The whole name length (counting also the space) must be between 2 and 25 characters long. Here some examples of names that have to match:

• Some Name


• SingleWordName

Here some examples of names that have not to match the regular expression:

• (a name full a space characters)


• Some Name (two spaces between Some and Name)

The last requirement is that I have to use this regular expression both in javascript and php.

Thanks in advance!

---

My Answer:
Here is a regular expression that meets your requirements:

javascript
/^[a-zA-Z]+(?: [a-zA-Z]+)?$/


Explanation:
- `^` : Start of the string
- `[a-zA-Z]+` : Match one or more letters
- `(?: [a-zA-Z]+)?` : Optionally match a space followed by one or more letters
- `$` : End of the string

This regular expression will match names that consist of one or two words with only letters and an optional space between them. It will not match names with more than one space character.

You can use this regular expression in both JavaScript and PHP like this:

JavaScript:
javascript
const regex = /^[a-zA-Z]+(?: [a-zA-Z]+)?$/;
const name = "Some Name";
if (regex.test(name)) {
console.log("Valid name");
} else {
console.log("Invalid name");
}


PHP:
php
$regex = '/^[a-zA-Z]+(?: [a-zA-Z]+)?$/';
$name = "Some Name";
if (preg_match($regex, $name)) {
echo "Valid name";
} else {
echo "Invalid name";
}


This regular expression should now correctly match the names you provided as examples.