Question

我在下面有一个if声明，用于检查数组中是否存在值，如果数值不存在则将其添加到数组中。显然，即使值在数组中，它也会再次触发它。

据我了解，它应该只显示每个值中的1个，因为它只会触发3次，如下所示：

Digital Photography -> 0
Step by Step Macintosh Training -> 0
How to become a Powerful Speaker -> 0

代码：

if (!in_array($unit['course_name'], $courseList)) {

  $courseList[$unit['course_name']]['name'] = $unit['course_name'];
  $courseList[$unit['course_name']]['seconds'] = 0;
  echo $courseList[$unit['course_name']]['name'] . ' -> ' . $courseList[$unit['course_name']]['seconds'];
  echo "<BR>";

}

但它输出：

Digital Photography -> 0
Step by Step Macintosh Training -> 0
Step by Step Macintosh Training -> 0
Step by Step Macintosh Training -> 0
How to become a Powerful Speaker -> 0
How to become a Powerful Speaker -> 0

以下是var_dump($unit)：

array(8) { ["author_name"]=> string(10) "tuiuiu_dev" [0]=> string(10) "tuiuiu_dev" ["course_name"]=> string(19) "Digital Photography" [1]=> string(19) "Digital Photography" ["unit_id"]=> string(3) "181" [2]=> string(3) "181" ["unit_quantity"]=> string(1) "1" [3]=> string(1) "1" } 
array(8) { ["author_name"]=> string(15) "William Merussi" [0]=> string(15) "William Merussi" ["course_name"]=> string(31) "Step by Step Macintosh Training" [1]=> string(31) "Step by Step Macintosh Training" ["unit_id"]=> string(3) "227" [2]=> string(3) "227" ["unit_quantity"]=> string(1) "1" [3]=> string(1) "1" } 
array(8) { ["author_name"]=> string(15) "William Merussi" [0]=> string(15) "William Merussi" ["course_name"]=> string(31) "Step by Step Macintosh Training" [1]=> string(31) "Step by Step Macintosh Training" ["unit_id"]=> string(3) "231" [2]=> string(3) "231" ["unit_quantity"]=> string(1) "1" [3]=> string(1) "1" } 
array(8) { ["author_name"]=> string(15) "William Merussi" [0]=> string(15) "William Merussi" ["course_name"]=> string(31) "Step by Step Macintosh Training" [1]=> string(31) "Step by Step Macintosh Training" ["unit_id"]=> string(3) "233" [2]=> string(3) "233" ["unit_quantity"]=> string(1) "1" [3]=> string(1) "1" } 
array(8) { ["author_name"]=> string(10) "tuiuiu_dev" [0]=> string(10) "tuiuiu_dev" ["course_name"]=> string(32) "How to become a Powerful Speaker" [1]=> string(32) "How to become a Powerful Speaker" ["unit_id"]=> string(4) "1080" [2]=> string(4) "1080" ["unit_quantity"]=> string(1) "1" [3]=> string(1) "1" } 
array(8) { ["author_name"]=> string(10) "tuiuiu_dev" [0]=> string(10) "tuiuiu_dev" ["course_name"]=> string(32) "How to become a Powerful Speaker" [1]=> string(32) "How to become a Powerful Speaker" ["unit_id"]=> string(4) "1084" [2]=> string(4) "1084" ["unit_quantity"]=> string(1) "1" [3]=> string(1) "1" }

感谢您的帮助！

Answer 1

in_array()方法检查数组值，而不是键。从您的示例中我可以看到，作为值，您有一个包含name和seconds字段的数组。我想你想检查你的数组中是否存在该ID。

所以if：

if (!in_array($unit['course_name'], $courseList)) {

应该这样改变：

if (!isset($courseList[$unit['course_name']])) {

通过这种方式，您可以检查数组中的$unit['course_name']是否为密钥。

Answer 2

如果您的数组仅包含值，则应使用in_array函数作为此示例：

$array = array("A", "B", "C");
in_array($string, $array) ? "found" : "not found";

否则，如果您有一个包含键的数组，则应使用isset函数作为此示例：

$array = array("A" => "Result A", "B" => "Result B", "C" => "Result C");
isset($array[$string]) ? "found" : "not found";

PHP in_array（）无法正常工作

2 个答案: