PHP 배열을 사용하여 데이터를 정렬하고 필터링하는 방법

$fruits = array("apple", "banana", "orange");
sort($fruits); // 按升序排序
print_r($fruits); // 输出：Array ( [0] => apple [1] => banana [2] => orange )

rsort($fruits); // 按降序排序
print_r($fruits); // 输出：Array ( [0] => orange [1] => banana [2] => apple )

$fruits = array("apple" => 2, "banana" => 5, "orange" => 3);
asort($fruits); // 按升序排序
print_r($fruits); // 输出：Array ( [apple] => 2 [orange] => 3 [banana] => 5 )

arsort($fruits); // 按降序排序
print_r($fruits); // 输出：Array ( [banana] => 5 [orange] => 3 [apple] => 2 )

$fruits = array("apple" => 2, "banana" => 5, "orange" => 3);
ksort($fruits); // 按键升序排序
print_r($fruits); // 输出：Array ( [apple] => 2 [banana] => 5 [orange] => 3 )

krsort($fruits); // 按键降序排序
print_r($fruits); // 输出：Array ( [orange] => 3 [banana] => 5 [apple] => 2 )

$numbers = array(1, 2, 3, 4, 5);
$new_numbers = array_filter($numbers, function ($value) {
    return $value % 2 === 0; // 筛选出偶数
});

print_r($new_numbers); // 输出：Array ( [1] => 2 [3] => 4 )

$numbers = array(1, 2, 3, 4, 5);
$new_numbers = array_map(function ($value) {
    return $value * 2; // 将每个元素乘以2
}, $numbers);

print_r($new_numbers); // 输出：Array ( [0] => 2 [1] => 4 [2] => 6 [3] => 8 [4] => 10 )

$fruits = array("apple", "banana", "orange");
array_walk($fruits, function (&$value) {
    $value = strtoupper($value); // 将每个元素转换为大写
});

print_r($fruits); // 输出：Array ( [0] => APPLE [1] => BANANA [2] => ORANGE )