I am trying to validate a comma separated list for numbers 1-8. i.e. <code>2,4,6,8,1</code> is valid input. I tried <code>[0-8,]*</code> but it seems to accept <code>1234</code> as valid. It is not requiring a comma and it is letting me type in a number larger than 8. I am not sure why.

<code>[0-8,]*</code> will match zero or more consecutive instances of <code>0</code> through <code>8</code> or <code>,</code>, anywhere in your string. You want something more like this: <pre class="prettyprint"><code>^[1-8](,[1-8])*$ </code></pre> <code>^</code> matches the start of the string, and <code>$</code> matches the end, ensuring that you're examining the entire string. It will match a single digit, plus zero or more instances of a comma followed by a digit after it.

Comma Separated Numbers Regex

1 Answers

[0-8,]* will match zero or more consecutive instances of 0 through 8 or ,, anywhere in your string. You want something more like this:

^[1-8](,[1-8])*$

^ matches the start of the string, and $ matches the end, ensuring that you're examining the entire string. It will match a single digit, plus zero or more instances of a comma followed by a digit after it.