PHP - 如何检查空数组？

问题描述：

Ok, this is easy, but I don't know why mine is not checking it!

I have an if statement that checks if an array is empty, if it's empty it should skip it, but all tries made not to skip it.

Here is the code:

$quizCounter = 0;
foreach ($quizzes as $key => $quiz) {

    if (!is_null($quiz['quiz_data'])) {

        echo "---->" . $key . "<BR>";

        unset($mark);
        $result = 0;
        $quizData = unserialize($quiz['quiz_data']);
        $quizTimestamp = date("d-m-Y", strtotime($quiz['time_stamp']));

        echo "Quiz: ";
        var_dump($quiz);
        echo "<BR>";

        echo "Quiz Data: ";
        var_dump($quizData);
        echo "<BR>";

        echo "Var Dump: ";
        var_dump($quizData['marks']);
        echo "<BR>";

        // Quiz marks
        if(!empty($quizData['marks'])) {
            foreach ($quizData['marks'] as $key => $marks) {
                $mark[$key] = $marks;
                echo "Mark: ";
                echo var_dump($marks) . "<BR>";
                $result += $marks;
            }
        }

        $markCounter = (count($mark) == 0) ? 1 : count($mark);
        $quizResult[$quizCounter] = $result / $markCounter;
        $quizCounter++;

    }

}

And here is the result that I need to skip:

---->34
Quiz: array(4) { ["quiz_data"]=> string(41) "a:2:{s:4:"ques";a:0:{}s:5:"marks";a:0:{}}" [0]=> string(41) "a:2:{s:4:"ques";a:0:{}s:5:"marks";a:0:{}}" ["time_stamp"]=> string(26) "0000-00-00 00:00:00.000000" [1]=> string(26) "0000-00-00 00:00:00.000000" } 
Quiz Data: array(2) { ["ques"]=> array(0) { } ["marks"]=> array(0) { } } 
Var Dump: array(0) { }

How may I skip this array?

好的，这很简单，但我不知道为什么我的不检查它！ p> \ n

我有一个if语句 code>来检查一个数组是否为空，如果它是空的，它应该跳过它，但所有的尝试都不会跳过它。 p> \ n

以下是代码： p>


  $ quizCounter = 0; 
foreach（$ quizzes as $ key =＆gt; $ quiz）{
 
 if（！）  is_null（$ quiz ['quiz_data']））{
 
 echo“----＆gt;”  。  $ key。  “＆lt; BR＆gt;”; 
 
未设置（$ mark）; 
 $ result = 0; 
 $ quizData = unserialize（$ quiz ['quiz_data']）; 
 $ quizTimestamp = date（“dmY”  ，strtotime（$ quiz ['time_stamp']））; 
 
 echo“测验：”; 
 var_dump（$ quiz）; 
 echo“＆lt; BR＆gt;”; 
 
 echo“测验数据：  “; 
 var_dump（$ quizData）; 
 echo”＆lt; BR＆gt;“; 
 
 echo”Var Dump：“; 
 var_dump（$ quizData ['marks']）; 
 echo”＆lt;  BR＆gt;“; 
 
 //测验标记
 if（！empty（$ quizData ['marks']））{
 foreach（$ quizData ['marks'] as $ key =＆gt; $ marks）{  
 $ mark [$ key] = $ marks; 
 echo“Mark：”; 
 echo var_dump（$ marks）。  “＆lt; BR＆gt;”; 
 $ result + = $ marks; 
} 
} 
 
 $ markCounter =（count（$ mark）== 0）？  1：count（$ mark）; 
 $ quizResult [$ quizCounter] = $ result / $ markCounter; 
 $ quizCounter ++; 
 
} 
 
} 
  code>  pre> 
  
 以下是我需要跳过的结果： p> 
 
 
  ----＆gt; 34 
Quiz：array（4）{[“quiz_data”]  =＆GT;  string（41）“a：2：{s：4：”ques“; a：0：{} s：5：”marks“; a：0：{}}”[0] =＆gt;  string（41）“a：2：{s：4：”ques“; a：0：{} s：5：”marks“; a：0：{}}”[“time_stamp”] =＆gt;  string（26）“0000-00-00 00：00：00.000000”[1] =＆gt;  string（26）“0000-00-00 00：00：00.000000”} 
测验数据：array（2）{[“ques”] =＆gt;  array（0）{} [“marks”] =＆gt;  array（0）{}} 
Var转储：array（0）{} 
  code>  pre> 
 
 我如何跳过这个数组？ p> 
  div  >

答

The following things are considered to be empty:

"" (an empty string)
0 (0 as an integer)
0.0 (0 as a float)
"0" (0 as a string)
NULL
FALSE
array() (an empty array)
$var; (a variable declared, but without a value)

This is a quote from the following page:

http://php.net/manual/en/function.empty.php

The reason why your code considers $quizData['marks'] as empty is because you have a variable equal to zero in $quizData['marks']. If you add another value that is not zero, your code should work.

Perhaps consider adding:

else if(isset($quizData['marks'])) {
    //proceed to print that person has a mark of zero
}

PHP - 如何检查空数组？

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