Velocity nulls和空字符串 [英] Velocity nulls and empty strings

问题描述

在速度中，我有一个变量，其值为 null 。在这种情况下，我不想显示任何内容。

In velocity I have a variable which its value is null. I don't want to display anything in that case.

目前模板引擎会将转换为 null ，所以我必须这样做。

Currently the template engine translates "" to null so I have to do.

#set ( $a = "")
#if ($a) 
   assert("never prints a neither gets here: " + $a)
#end

有没有办法我可以直接这样做吗？我希望能够做出类似的结果：

Is there a way I could do that directly? I'd like to be able to make something like:

This is the variable $a. ## in case that $a is null i don't want 'dollar a' to be displayed

推荐答案

$！a诀窍。您可以直接使用此表单而无需检查。

$!a does the trick. You can use this form directly without an if check.

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