关于PHP数组相关的常用函数

PHP是一种非常强大的编程语言，其中的数组函数是开发中经常用到的。下面列出了一些PHP中关于数组的常用函数以及相应的示例代码：

1. array_push() - 将一个或多个元素压入数组的末尾

$stack = array("orange", "banana");
array_push($stack, "apple", "raspberry");
print_r($stack);

输出:

Array
(
    [0] => orange
    [1] => banana
    [2] => apple
    [3] => raspberry
)

2. array_pop() - 删除并返回数组的最后一个元素

$stack = array("orange", "banana", "apple");
$fruit = array_pop($stack);
print_r($stack);
echo $fruit;

输出:

Array
(
    [0] => orange
    [1] => banana
)
apple

3. array_shift() - 删除并返回数组的第一个元素

$queue = array("orange", "banana", "apple");
$fruit = array_shift($queue);
print_r($queue);
echo $fruit;

输出:

Array
(
    [0] => banana
    [1] => apple
)
orange

4. array_unshift() - 在数组开头插入一个或多个元素

$queue = array("orange", "banana");
array_unshift($queue, "apple", "raspberry");
print_r($queue);

输出:

Array
(
    [0] => apple
    [1] => raspberry
    [2] => orange
    [3] => banana
)

5. array_merge() - 合并一个或多个数组

$array1 = array("color" => "red", 2, 4);
$array2 = array("a", "b", "color" => "green", "shape" => "trapezoid", 4);
$result = array_merge($array1, $array2);
print_r($result);

输出:

Array
(
    [color] => green
    [0] => 2
    [1] => 4
    [2] => a
    [3] => b
    [shape] => trapezoid
    [4] => 4
)

6. array_reverse() - 返回一个元素顺序颠倒的数组

$input  = array("php", 4.0, "green", "red");
$reversed = array_reverse($input);
print_r($reversed);

输出:

Array
(
    [0] => red
    [1] => green
    [2] => 4
    [3] => php
)

7. array_keys() - 返回数组中所有的键名

$array = array("blue" => "sky", "green" => "grass", "red" => "apple");
print_r(array_keys($array));

输出:

Array
(
    [0] => blue
    [1] => green
    [2] => red
)

8. array_values() - 返回数组中所有的值

$array = array("blue" => "sky", "green" => "grass", "red" => "apple");
print_r(array_values($array));

输出:

Array
(
[0] => sky
[1] => grass
[2] => apple
)

9. count() - 返回数组中的元素数目

$array = array("orange", "banana", "apple");
echo count($array);

输出:

3

10. in_array() - 检查一个值是否存在于数组中

$fruits = array("orange", "banana", "apple");
if (in_array("apple", $fruits)) {
    echo "Got apple!";
}

输出:

Got apple!

以上是一些常见的PHP数组函数的示例代码。