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PHP Array reversal has the following uses: getting the last element, traversing in reverse order, and creating a descending array. There are two methods of reversal: 1. array_reverse() function; 2. Use for loop. For example, to print a student resume in reverse order: first use array_reverse() to reverse the array, then traverse the reversed array in reverse order, outputting the name, age, and skills of each student.
#Why do you need to reverse a PHP array?
In PHP, array reversal is very useful in the following situations:
Two methods to reverse PHP array
1. array_reverse() function
<?php $arr = [1, 2, 3, 4, 5]; // 反转数组 $reversed_arr = array_reverse($arr); // 打印反转数组 print_r($reversed_arr); ?>
2. Using a For loop
<?php $arr = [1, 2, 3, 4, 5]; // 创建一个新数组来存储反转后的元素 $reversed_arr = []; // 使用 for 循环倒序遍历 original 数组 for ($i = count($arr) - 1; $i >= 0; $i--) { // 将元素添加到 reversed 数组的开头 array_unshift($reversed_arr, $arr[$i]); } // 打印反转数组 print_r($reversed_arr); ?>
Practical case
Print students’ resumes in reverse order
// 模拟学生履历表数组 $students = [ ['name' => 'John', 'age' => 21, 'skills' => ['PHP', 'JavaScript']], ['name' => 'Jane', 'age' => 22, 'skills' => ['HTML', 'CSS']], ['name' => 'Bob', 'age' => 23, 'skills' => ['Java', 'Python']], ]; // 使用 array_reverse() 反转数组 $reversed_students = array_reverse($students); // 倒序遍历反转的数组 foreach ($reversed_students as $student) { echo "Name: {$student['name']}, Age: {$student['age']}, Skills: "; foreach ($student['skills'] as $skill) { echo "$skill "; } echo "<br>"; }
This code will print the student's resume in reverse order:
Name: Bob, Age: 23, Skills: Java Python Name: Jane, Age: 22, Skills: HTML CSS Name: John, Age: 21, Skills: PHP JavaScript
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