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
       )

以及一个多维的已完成课程数组，如下所示：

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
                )

       )
)

如果它存在于第一个数组中，我只想回显课程、标题和成绩。 我想我需要一个 foreach 循环，但我被卡住了。

Answer 1

您走在正确的轨道上，因为您需要遍历多维数组值，然后查看课程是否在您的课程数组中。 这可以通过将 foreach 与 in_array 函数结合使用来完成。

<?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

您可能正在寻找array_flip函数，而不是很简单。

<?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

您可以遍历数组（假设变量名称）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;