PHP prev() 函数

<?php
 $people = array("Peter", "Joe", "Glenn", "Cleveland");

 echo current($people) . "<br>";
 echo next($people) . "<br>";
 echo prev($people);
 ?>

定义和用法

prev() 函数将内部指针指向数组中的上一个元素，并输出。

相关的方法：

• next() - 将内部指针指向数组中的下一个元素，并输出。
• current() - 返回数组中的当前元素的值。
• end() - 将内部指针指向数组中的最后一个元素，并输出。
• reset() - 将内部指针指向数组中的第一个元素，并输出。
• each() - 返回当前元素的键名和键值，并将内部指针向前移动。

语法

prev(array)

技术细节

更多实例

<?php
 $people = array("Peter", "Joe", "Glenn", "Cleveland");

echo current($people) . "<br>"; // The current element is Peter
echo next($people) . "<br>"; // The next element of Peter is Joe
echo current($people) . "<br>"; // Now the current element is Joe
echo prev($people) . "<br>"; // The previous element of Joe is Peter
echo end($people) . "<br>"; // The last element is Cleveland
echo prev($people) . "<br>"; // The previous element of Cleveland is Glenn
echo current($people) . "<br>"; // Now the current element is Glenn
echo reset($people) . "<br>"; // Moves the internal pointer to the first element of the array, which is Peter
 echo next($people) . "<br>"; // The next element of Peter is Joe

 print_r (each($people)); // Returns the key and value of the current element (now Joe), and moves the internal pointer forward
?>