树枝：如果有多个条件

似乎我的树枝if语句有问题。

{%if fields | length > 0 || trans_fields | length > 0 -%}

错误是：

Unexpected token "punctuation" of value "|" ("name" expected) in 

我不明白为什么这行不通，就像树枝被所有管道弄丢了一样。

我已经试过了：

{% set count1 = fields | length %}
{% set count2 = trans_fields | length %}
{%if count1 > 0 || count2 > 0 -%}

但如果也失败。

然后尝试这个：

{% set count1 = fields | length > 0 %}
{% set count2 = trans_fields | length > 0 %}
{%if count1 || count2 -%}

而且它仍然不起作用，每次都出现相同的错误...

所以...这引出我一个非常简单的问题：Twig是否支持多个条件IF？

如果我没记错的话，Twig不支持||和&&运算符，但要求or和and分别使用。我也将使用括号更清楚地表示这两个语句，尽管从技术上讲这不是必需的。

{%if ( fields | length > 0 ) or ( trans_fields | length > 0 ) %}

表达方式

Expressions can be used in {% blocks %} and ${ expressions }.

Operator    Description
==          Does the left expression equal the right expression?
+           Convert both arguments into a number and add them.
-           Convert both arguments into a number and substract them.
*           Convert both arguments into a number and multiply them.
/           Convert both arguments into a number and divide them.
%           Convert both arguments into a number and calculate the rest of the integer division.
~           Convert both arguments into a string and concatenate them.
or          True if the left or the right expression is true.
and         True if the left and the right expression is true.
not         Negate the expression.

对于更复杂的操作，最好将单个表达式括在括号中以避免混淆：

{% if (foo and bar) or (fizz and (foo + bar == 3)) %}