如何在 ftl 的 <#if> 语句中使用返回 boolean 的方法

Question

So, in Java, you can call some methods that return Boolean on a String , for example, string.startsWith("substring") . I want to use this in the ftl file, but for some reason this does not work.

<#if string.startsWith("substring")></#if>

I am pretty new to ftl, I just started learning it today, but, why this does not work? In java, if statement accepts Boolean , startsWith method returns Boolean , so, what is the problem here?

Error is: Expected a hash, but this has evaluated to a string . I do not get it, how can if statement receive a hash?? Should not it receive a Boolean ?

Answer 1

Most Java String methods are hidden in FTL. You have to instead use an FTL builtin. In your case, use

<#if string?starts_with("substring")></#if>

See documentation