元名稱不區分大小寫

Question

我有以下基於常規WordPress自定義字段名稱的GET功能。 當打勾時，它將所有具有該自定義字段值設置爲1的帖子排序。 它當前有效。但是，我碰巧有兩個自定義字段：'free'和'twofree'

當我勾選'free'時，它還包含'twofree'，反之亦然。它似乎並不區分大小寫。有沒有解決這個問題？

<?php 
/* my code starts from here*/ 
if(isset($_GET['show']) && !empty ($_GET['show'] ) ){ 
    if($_GET['show'] == 1) 
    $meta_field = 'free'; 
    else if($_GET['show'] == 4) 
    $meta_field = 'sale'; 
    else if($_GET['show'] == 2) 
    $meta_field = 'genuine'; 
    else if ($_GET['show'] == 'onfire') 
    $meta_field = 'onfire'; 
    else if($_GET['show'] == 5) 
    $meta_field = 'twofree';  
else if($_GET['show'] == 3) 
    $meta_field = 'onfire'; 

     if($_GET['show'] == 'sale') 
      query_posts('cat='.$cat.'&meta_key='.$meta_field.'&meta_value > 0'); 
     else 
      query_posts('cat='.$cat.'&meta_key='.$meta_field.'&meta_value>=1'); 
} 
/* my code ends from here*/ 
?> 

編輯：我已經發現了這個問題，並在部分

query_posts('cat='.$cat.'&meta_key='.$meta_field.'&meta_value>=1'); 

騙我改成了

query_posts('cat='.$cat.'&meta_key='.$meta_field.'&meta_value=1'); 

Answer 1

使用身份操作時要匹配精確值===，而不是==，它根據字符串/整數檢查相似的值。

---

更多一個這個問題，看看這個link或這個答案下面

Using the `==` operator (*Equality*) 

    true == 1; //true, because 'true' is converted to 1 and then compared 
    "2" == 2 //true, because 2 is converted to "2" and then compared 

Using the `===` operator (*Identity*) 

    true === 1 //false 
    "2" === 2 // false 

This is because the **equality operator == does type coercion**...meaning that the interpreter implicitly tries to convert the values and then does the comparing. 

On the other hand, the **identity operator === does not do type coercion**, and so thus it does not convert the values of the values when comparing