{if},{elseif},{else}

Smarty的{if}条件判断和PHP的if 非常相似,只是增加了一些特性。 每个{if}必须有一个配对的{/if}. 也可以使用{else}{elseif}. 全部的PHP条件表达式和函数都可以在if内使用,如||, or, &&, and, is_array(), 等等.

如果开启了安全机制,那么只有在$php_functions设置允许的PHP函数才能使用。 参见安全机制

下面是可用的运算符列表,使用中都会放到元素的中间并且用空格分隔。 注意列表中[方括号]的是可选的,而且还会列出对应PHP的表达式。

运算符 别名 语法示例 含义 对应PHP语法
== eq $a eq $b 等于 ==
!= ne, neq $a neq $b 不等于 !=
> gt $a gt $b 大于 >
< lt $a lt $b 小于 <
>= gte, ge $a ge $b 大于等于 >=
<= lte, le $a le $b 小于等于 <=
=== $a === 0 绝对等于 ===
! not not $a 非 (一元运算) !
% mod $a mod $b 取模 %
is [not] div by $a is not div by 4 取模为0 $a % $b == 0
is [not] even $a is not even [非] 取模为0 (一元运算) $a % 2 == 0
is [not] even by $a is not even by $b 水平分组 [非] 平均 ($a / $b) % 2 == 0
is [not] odd $a is not odd [非] 奇数 (一元运算) $a % 2 != 0
is [not] odd by $a is not odd by $b [非] 奇数分组 ($a / $b) % 2 != 0

Example 7.44. {if} 表达式


{if $name eq 'Fred'}
    Welcome Sir.
{elseif $name eq 'Wilma'}
    Welcome Ma'am.
{else}
    Welcome, whatever you are.
{/if}

{* an example with "or" logic *}
{if $name eq 'Fred' or $name eq 'Wilma'}
   ...
{/if}

{* same as above *}
{if $name == 'Fred' || $name == 'Wilma'}
   ...
{/if}


{* parenthesis are allowed *}
{if ( $amount < 0 or $amount > 1000 ) and $volume >= #minVolAmt#}
   ...
{/if}


{* you can also embed php function calls *}
{if count($var) gt 0}
   ...
{/if}

{* check for array. *}
{if is_array($foo) }
   .....
{/if}

{* check for not null. *}
{if isset($foo) }
   .....
{/if}


{* test if values are even or odd *}
{if $var is even}
   ...
{/if}
{if $var is odd}
   ...
{/if}
{if $var is not odd}
   ...
{/if}


{* test if var is divisible by 4 *}
{if $var is div by 4}
   ...
{/if}


{*
  test if var is even, grouped by two. i.e.,
  0=even, 1=even, 2=odd, 3=odd, 4=even, 5=even, etc.
*}
{if $var is even by 2}
   ...
{/if}

{* 0=even, 1=even, 2=even, 3=odd, 4=odd, 5=odd, etc. *}
{if $var is even by 3}
   ...
{/if}

  

Example 7.45. {if} 的更多例子

 
{if isset($name) && $name == 'Blog'}
     {* do something *}
{elseif $name == $foo}
    {* do something *}
{/if}

{if is_array($foo) && count($foo) > 0}
    {* do a foreach loop *}
{/if}