freemarker 自定义变量

	<#assign voteIds='' />
        <#assign voteNames='' />
        <#if (wendaQuestion.voteList)?? && (wendaQuestion.voteList)?size gt 0>
        <#list (wendaQuestion.voteList) as vote>
            <#assign voteIds = voteIds + vote?if_exists.id?if_exists +',' />
            <#assign voteNames = voteNames + vote?if_exists.voteDescribe?if_exists +',' />