Grails GSP <g:set> tag set as integer?

Use the ${} syntax when defining the value. For example:

<g:set var="x" value="${100}"/>

You can see the tag doc for g:set for more info.

Just as an additional comment for someone who comes across this since it is the only useful result on the Internet for and casting/Int/Sring/etc. This example works in the case of variables:

<g:set var="printLeft" value="${offer?.metaInfo?.redeemPrintY as Integer}"/>
<g:set var="printTop" value="${offer?.metaInfo?.redeemPrintX as Integer}"/>
<g:set var="printWidth" value="${offer?.metaInfo?.redeemPrintW as Integer}"/>
<g:set var="printHeight" value="${offer?.metaInfo?.redeemPrintH as Integer}"/>

...

<area shape="rect" coords="${printLeft},${printTop},${printLeft+printWidth},${printTop+printHeight}" onClick="printOffer();" />