获取多维数组的值，其中键值在另一个数组中

Question

我有一系列课程：

Array
(
[0] => BIOL-1108
[1] => BIOL-1308
[2] => BIOL-2401
[3] => BIOL-2402
)

还有一个多维的已完成课程数组，看起来像这样：

Array
(
[course] => Array
(
[0] => Array
(
[course] => BIOL-2401
[title] => BIOL-2401 - Human Anatomy & Physiology I
[grade] => A
)
[1] => Array
(
[course] => HIST-1301
[title] => HIST-1301 - History of the U.S. I
[grade] => B
)
[2] => Array
(
[course] => MATH-0303
[title] => MATH-0303 - Intermediate Algebra
[grade] => F
)
[3] => Array
(
[course] => BIOL-1108
[title] => BIOL-1108 - Life Science I Lab
[grade] => B
)
[4] => Array
(
[course] => BIOL-1308
[title] => BIOL-1308 - Life Science I
[grade] => C
)
)
)

如果课程、标题和成绩存在于第一个数组中，我只想回显它。我想我需要一个前臂环，但我卡住了。

Answer 1

您正走在正确的轨道上，因为您需要在多维数组值上循环，然后查看课程是否在课程数组中。这可以使用foreach和in_array函数来完成。

<?php

$courses = array('BIOL-1108', 'BIOL-1308', 'BIOL-2401','BIOL-2402');
$completed_courses = array(
'course' => array(
array(
'course' => 'BIOL-2401',
'title' => 'BIOL-2401 - Human Anatomy & Physiology I',
'grade' => 'A'
),
array(
'course' => 'HIST-1301',
'title' => 'HIST-1301 - History of the U.S. I',
'grade' => 'B'
),
array
(
'course' => 'MATH-0303',
'title' => 'MATH-0303 - Intermediate Algebra',
'grade' => 'F'
),
array
(
'course' => 'BIOL-1108',
'title' => 'BIOL-1108 - Life Science I Lab',
'grade' => 'B'
),
array
(
'course' => 'BIOL-1308',
'title' => 'BIOL-1308 - Life Science I',
'grade' => 'C'
)
)
);

foreach( $completed_courses['course'] as $curr ){
if(in_array($curr['course'], $courses)) {
echo 'COURSE : ' . $curr['course'] . PHP_EOL;
echo 'TITLE : ' .  $curr['title'] . PHP_EOL;
echo 'GRADE : ' .  $curr['grade'] . PHP_EOL;
}
}

Answer 2

您可能正在查找array_flip函数，而不是简单地查找。

<?php
$courses = [
'BIOL-1108',
'BIOL-1308'
];
$completed = [
'course' => [
[
'course' => 'BIOL-1108',
'title' => 'title',
'grade' => 'C'
],
[
'course' => 'BIOL-1308',
'title' => 'title',
'grade' => 'C'
],
[
'course' => 'BIOL-1408',
'title' => 'title',
'grade' => 'C'
]
]
];

$courses = array_flip($courses);
foreach ($completed['course'] as $row) {
if (!isset($courses[$row['course']])) {
echo $row['course'] . '<BR>'; // returns BIOL-1408 in my example
}
}

Answer 3

您可以循环遍历数组(假设变量名(，并使用in_array检查课程标题是否存在。

foreach($user['course'] as $course):
if(in_array($course['title'], $completedCourses)):
printf('Title: %s, Grade: %s', $course['title'], $course['grade']);
endif;
endforeach;