php 数组前面添加元素

<?php
$array = array("apple", "banana", "cherry");
echo "原始数组: ";
print_r($array);

// 向数组前面添加一个元素
array_unshift($array, "date");
echo "添加一个元素后的数组: ";
print_r($array);

// 向数组前面添加多个元素
array_unshift($array, "fig", "grape");
echo "添加多个元素后的数组: ";
print_r($array);
?>

原始数组: Array ( [0] => apple [1] => banana [2] => cherry )
添加一个元素后的数组: Array ( [0] => date [1] => apple [2] => banana [3] => cherry )
添加多个元素后的数组: Array ( [0] => fig [1] => grape [2] => date [3] => apple [4] => banana [5] => cherry )

<?php
$array = array("apple", "banana", "cherry");
echo "原始数组长度: " . count($array) . "\n";

// 确保传入正确的参数
if (!empty($array)) {
    array_unshift($array, "date");
    echo "添加元素后的数组长度: " . count($array) . "\n";
} else {
    echo "数组为空，无法添加元素。\n";
}
?>