{if},{elseif},{else}

Smarty 的{if} 语句具有与 PHP if 语句基本相同的灵活性，并为模板引擎添加了一些新增功能。每个 {if} 都必须与匹配的 {/if} 配对。还允许使用 {else} 和 {elseif}。所有 运算符 都被认可，例如 ==、||、or、&&、and 等，并且可以使用修饰符作为函数，例如 is_array()。

示例

{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}

{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}