Regex to match number of chars in groups separated by dashes? - regex

Question

Here is the string I want to match 76c24efd-ec42-492a-92df-c62cfd4540a3. The following regex will match a 36 char length string with alphanumeric characters and '-'.
[a-zA-Z0-9\-]{36}
I am trying to add to this regex, so it matches only when <8 chars> - <4 chars> - <4 chars> - <4 chars> - <12 chars>

Answer 1

The following will match a group of 8 characters followed by a dash, then a group of 4 characters followed by a dash 3 times, and then a group of 12 characters.
^[a-z0-9]{8}-(?:[a-z0-9]{4}-){3}[a-z0-9]{12}$/
Here's a short JavaScript test that shows the results.
$('.test').each(function(row, item) {
var val = $($(item).children()[0]).html()
var result = /^[a-z0-9]{8}-(?:[a-z0-9]{4}-){3}[a-z0-9]{12}$/gi.test(val);
$($(item).children()[1]).html(result.toString())
});
th {
text-align:left;
padding-right:10px;
}
td {
border: 1px solid #ccc;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<table style="border: 1px solid black">
<tr><th>Test</th><th>Result</th><th>Desired Result</th></tr>
<tr class="test"><td>76c24efd-ec42-492a-92df-c62cfd4540a3</td><td></td><td>Good</td></tr>
<tr class="test"><td>76c24efd-ecz42-492a-92df-c62cfd4540a3</td><td></td><td>Bad Length - 2nd segment too long</td></tr>
<tr class="test"><td>76c24efd-ec2-492a-92df-c62cfd4540a31</td><td></td><td>Bad Segment Lengths</td></tr>
<tr class="test"><td>76$24efd-ec42-492a-92df-c62cfd4540a3</td><td></td><td>Bad Char ($)</td></tr>
</table>