<%、<%=、<%#和-%>之间的区别是什么?在Rails中的ERB中?

问题描述：

有人可以描述一下ERB文件中使用的以下字符的用法:

Can some one please describe the usage of the following characters which is used in ERB file:

<%   %>
<%=  %>
<%  -%>
<%#  %>

每一个的用途是什么?

答

<% %>

执行括号内的 ruby 代码.

Executes the ruby code within the brackets.

<%= %>

将某些内容打印到 erb 文件中.

Prints something into erb file.

<%== %>

相当于 .将某些内容逐字打印(即没有转义)到 erb 文件中.(摘自 Ruby on Rails 指南.)

Equivalent to <%= raw %>. Prints something verbatim (i.e. w/o escaping) into erb file. (Taken from Ruby on Rails Guides.)

<% -%>

避免在表达式后换行.

<%# %>

注释掉括号内的代码；不发送给客户端(与 HTML 注释相反).

Comments out code within brackets; not sent to client (as opposed to HTML comments).

访问 Ruby 文档了解更多信息关于ERB.

Visit Ruby Doc for more infos about ERB.