如预期foreach循环不输阵 [英] Foreach loop not outputting arrays as expected

问题描述

我有一个名为对象 Thread_category 。这有一个名为 find_all_by_category（$类）方法，输出具有类线程的数组， $类别。

我有一个数组 $ category_array_for_this_thread ，它输出：

 阵列（[0] =＆GT;变应性疾病[1] =＆GT;过敏性哮喘[2] =＆GT;先天性肺疾病[3] =＆GT;特发性肺纤维化）
 

现在，如果我这样做

  $ test1的= Thread_category :: find_all_by_category（'过敏性疾病'）;
    的print_r（$ test1的）;
    回声＆LT; BR /＆gt;中;
    回声＆LT; BR /＆gt;中;    $ TEST2 = Thread_category :: find_all_by_category（'过敏性哮喘'）;
    的print_r（$测试2）;
    回声＆LT; BR /＆gt;中;
    回声＆LT; BR /＆gt;中;    $ TEST3 = Thread_category :: find_all_by_category（'先天性肺病'）;
    的print_r（$ TEST3）;
    回声＆LT; BR /＆gt;中;
    回声＆LT; BR /＆gt;中;    $ TEST4 = Thread_category :: find_all_by_category（特发性肺纤维化'）;
    的print_r（$ TEST4）;
    回声＆LT; BR /＆gt;中;
    回声＆LT; BR /＆gt;中;
 

我得到

 阵列（[0] =＆GT; Thread_category对象（[ID] =＆GT; 2 [thread_id单] =＆GT; 145类别] =＆GT;过敏性疾病）[1] = ＆GT; Thread_category对象（[ID] =＆GT; 10的thread_id] =＆GT; 146【类别】=＆GT;过敏性疾病）[2] =＆GT; Thread_category对象（[ID] =＆GT; 20的thread_id] =＆GT; 147【类别】=＆GT;过敏性疾病））阵列（[0] =＆GT; Thread_category对象（[ID] =＆GT; 21 [thread_id单] =＆GT; 147【类别】=＆GT;哮喘）[1] =＆GT; Thread_category对象（[ID] =＆GT; 24 [的thread_id] =＆GT; 148【类别】=＆GT;过敏性哮喘））阵列（[0] =＆GT; Thread_category对象（[ID] =＆GT; 4的thread_id] =＆GT; 145类别] =＆GT;先天性肺病）[1] =＆GT; Thread_category对象（[ID] =＆GT; 22的thread_id] =＆GT; 147【类别】=＆GT;先天性肺病）[2] =＆GT; Thread_category对象（[ID] =＆GT; 25的thread_id] =＆GT; 148【类别】=＆GT;先天性肺部疾病））阵列（[0] =＆GT; Thread_category对象（[ID] =＆GT; 5的thread_id] =＆GT; 145类别] =＆GT;特发性肺纤维化）[1] =＆GT; Thread_category对象（[ID] =＆GT; 11 [thread_id单] =＆GT; 146【类别】=＆GT;特发性肺纤维化））
 

但是！

如果我这样做

 的foreach（$ category_array_for_this_thread为$类）{
                    回声$类别。 ＆LT; BR /＆gt;中;
        $ test_array = Thread_category :: find_all_by_category（$类）;
        的print_r（$ test_array）;
        }
 

我得到这个....

 过敏性疾病
   阵列（[0] =＆GT; Thread_category对象（[ID] =＆GT; 2 [thread_id单] =＆GT; 145类别] =＆GT;过敏性疾病）[1] =＆GT; Thread_category对象（[ID] =＆GT; 10 [thread_id单] =＆GT; 146【类别】=＆GT;过敏性疾病）[2] =＆GT; Thread_category对象（[ID] =＆GT; 20的thread_id] =＆GT; 147【类别】=＆GT;过敏性疾病））
   过敏性哮喘
   阵列（）
   先天性肺部疾病
   阵列（）
   特发性肺纤维化
   阵列（）
 

我能看到的唯一区别是，第二个是在foreach循环。为什么我收到3个空数组有人能向我解释

下面是方法......

 公共静态功能find_all_by_category（$类）{
    返回self ::的find_by_sql（SELECT * FROM thread_category WHERE类='{$}类'）;
 

}

解决方案

您数组的第二个元素值为过敏，但你需要有哮喘。难道说，这将引发你的 find_all_by_category 功能 - 它解释了为什么第二个元素是空的，也许功能做一些奇怪的是没有发现赛后

I have an object called Thread_category. This has a method called find_all_by_category($category) which outputs an array of threads that have the category, $category.

I have an array $category_array_for_this_thread which outputs:

Array ( [0] => Allergic diseases [1] => Allergic asthma [2] => Congenital lung disease [3] => Idiopathic pulmonary fibrosis ) 

Now, if I do this

    $test1 = Thread_category::find_all_by_category('Allergic diseases');
    print_r($test1);
    echo "<br/>";
    echo "<br/>";

    $test2 = Thread_category::find_all_by_category('Allergic asthma');
    print_r($test2);
    echo "<br/>";
    echo "<br/>";

    $test3 = Thread_category::find_all_by_category('Congenital lung disease');
    print_r($test3);
    echo "<br/>";
    echo "<br/>";

    $test4 = Thread_category::find_all_by_category('Idiopathic pulmonary fibrosis');
    print_r($test4);
    echo "<br/>";
    echo "<br/>";

I get

Array ( [0] => Thread_category Object ( [id] => 2 [thread_id] => 145 [category] => Allergic diseases ) [1] => Thread_category Object ( [id] => 10 [thread_id] => 146 [category] => Allergic diseases ) [2] => Thread_category Object ( [id] => 20 [thread_id] => 147 [category] => Allergic diseases ) ) 

Array ( [0] => Thread_category Object ( [id] => 21 [thread_id] => 147 [category] => Asthma ) [1] => Thread_category Object ( [id] => 24 [thread_id] => 148 [category] => Allergic asthma ) ) 

Array ( [0] => Thread_category Object ( [id] => 4 [thread_id] => 145 [category] => Congenital lung disease ) [1] => Thread_category Object ( [id] => 22 [thread_id] => 147 [category] => Congenital lung disease ) [2] => Thread_category Object ( [id] => 25 [thread_id] => 148 [category] => Congenital lung disease ) ) 

Array ( [0] => Thread_category Object ( [id] => 5 [thread_id] => 145 [category] => Idiopathic pulmonary fibrosis ) [1] => Thread_category Object ( [id] => 11 [thread_id] => 146 [category] => Idiopathic pulmonary fibrosis ) )

BUT!

if I do this

        foreach($category_array_for_this_thread as $category){
                    echo $category . "<br/>";
        $test_array = Thread_category::find_all_by_category($category);
        print_r($test_array);
        }

I get this....

   Allergic diseases
   Array ( [0] => Thread_category Object ( [id] => 2 [thread_id] => 145 [category] =>    Allergic diseases ) [1] => Thread_category Object ( [id] => 10 [thread_id] => 146 [category] => Allergic diseases ) [2] => Thread_category Object ( [id] => 20 [thread_id] => 147 [category] => Allergic diseases ) ) 
   Allergic asthma
   Array ( ) 
   Congenital lung disease
   Array ( ) 
   Idiopathic pulmonary fibrosis
   Array ( )

The only difference I can see is that the second is in a foreach loop. Can someone explain to me why I am getting 3 empty arrays

Here is the method....

       public static function find_all_by_category($category) {
    return self::find_by_sql("SELECT * FROM thread_category WHERE category='{$category}'");

}

解决方案

The second element of your array has the value Allergic but you need it to have Asthma. Could it be that this throws your find_all_by_category function off - it explains why the second element is empty, and maybe the function does something strange after it has found no match?

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