Question

I’m trying to make a regular expression to validate this pattern:

This is a text
[TEXT][SINGLE SPACE][TEXT][SINGLE SPACE][TEXT][SINGLE SPACE][TEXT]
A personal name
William Smith
[TEXT][SINGLE SPACE][TEXT]
Another text
[TEXT][SINGLE SPACE][TEXT][SINGLE SPACE]

The pattern will contain the next rules:

• Not start with any space
• The string can contain just a single space between words or a single space at the end of the string

I have this regular expression

/^[[A-Za-z0-9]+\s?[A-Za-z0-9]*]{0,10}$/

But I don’t know how to repeat the pattern and make it 10 of length

** Edit **

To make a more understandable, I’m working on a jQuery plugin that bind a keypress event to a input text element, and then add an expression to validate in each key pressed the text, is like a masked textbox, so to apply the rules for a mask that accept just alphanumeric characters and a space between the words I need the expression validate each key pressed like this

T
Th
This
This
This i
This is
This is
This is a
This is a
This is a t
This is a te
This is a tex
This is a text

Answer 1

OK, well, I think I’ve understood the requirements correctly.

First, this matches a single word followed by exactly one space:

/[a-zA-Z01-9]+ /

Then we need to repeat that 10 times, right? Starting from the beginning?

/^([a-zA-Z01-9]+ ){10}/

But the trailing space is optional, yes?

/^([a-zA-Z01-9]+ ){9}[a-zA-Z01-9]+ ?$/

Also, it would probably be better to use \w rather than [a-zA-Z01-9].¹ And \s would match any whitespace, which might be better than matching only spaces.

If you meant up to 10 times, that should be {0,9} instead of {9}.

¹ \w would match underscores, as well as various international letters, which your original pattern wouldn’t. Wasn’t sure if that was intentional, so I didn’t use it, but if it wasn’t intentional then \w is a better choice.