TWIG的 tests 学习

做逻辑判断的。目前支持的有

divisibleby null even odd sameas constant defined empty

 

 

divisibleby
检查是否能被整除

{% if loop.index is divisibleby(3) %} 
    ... 
{% endif %} 
{% if loop.index is divisibleby(3) %}
    ...
{% endif %}

 

null
{{ var is null }} 
{{ var is null }}

 

even
变量是否是偶数{{ var is even }} 
{{ var is even }}

odd
变量是否是奇数

{{ var is odd }} <br>
<pre name="code" class="html">{{ var is odd }}
<p> </p>
<p> </p>
<p>sameas<br>
检查变量的地址是否相同</p>
<p>{% if foo.attribute is sameas(false) %} <br>
    the foo attribute really is the ``false`` PHP value <br>
{% endif %} <br>
{% if foo.attribute is sameas(false) %}<br>
    the foo attribute really is the ``false`` PHP value<br>
{% endif %}</p>
<p> </p>
<p>constant<br>
检查变量的值是否相同</p>
<p>{% if post.status is constant('Post::PUBLISHED') %} <br>
    the status attribute is exactly the same as Post::PUBLISHED <br>
{% endif %} <br>
{% if post.status is constant('Post::PUBLISHED') %}<br>
    the status attribute is exactly the same as Post::PUBLISHED<br>
{% endif %}</p>
<p> </p>
<p>defined<br>
测试变量是否定义</p>
<p>{# defined works with variable names #} <br>
{% if foo is defined %} <br>
    ... <br>
{% endif %} <br>
 <br>
{# and attributes on variables names #} <br>
{% if foo.bar is defined %} <br>
    ... <br>
{% endif %} <br>
 <br>
{% if foo['bar'] is defined %} <br>
    ... <br>
{% endif %} <br>
{# defined works with variable names #}<br>
{% if foo is defined %}<br>
    ...<br>
{% endif %}</p>
<p>{# and attributes on variables names #}<br>
{% if foo.bar is defined %}<br>
    ...<br>
{% endif %}</p>
<p>{% if foo['bar'] is defined %}<br>
    ...<br>
{% endif %}</p>
<p> </p>
<p>empty<br>
测试变量是否为空，empty的意思是：该变量已经定义，但他的值是 null false 或者是空字符串<br>
{# evaluates to true if the foo variable is null, false, or the empty string #} <br>
{% if foo is empty %} <br>
    ... <br>
{% endif %} <br>
<br>
摘自 jiaochangyun的专栏</p>