収集する価値のある 20 以上の一般的な PHP ヒント (共有)

public function __construct()
{
    parent::__construct();
    header('Access-Control-Allow-Origin:*');    //跨域
}

die( json_encode( $result,JSON_UNESCAPED_UNICODE ) );

$users = array(
    array('name' => 'xiao1', 'age' => 20),
    array('name' => 'xiao2', 'age' => 18),
    array('name' => 'xiao3', 'age' => 22)
);
 
/*按照年龄升序*/
//要将age提取出来存储到一维数组里，然后按照age升序排列
$ages= array_column($users, 'age');
array_multisort($ages, SORT_ASC, $users);
 
/*先按照年龄升序，再按照姓名降序*/
$ages= array_column($users, 'age');
$names = array_column($users, 'name');
array_multisort($ages, SORT_ASC, $names, SORT_DESC, $users);

ini_set("display_errors", "On");
error_reporting(E_ALL | E_STRICT);

//list使用
public function test(){
    list($name, $sex) = $this->getInfo();
    echo "姓名：{$name}，性别：{$sex}";
}
 
public function getInfo(){
    return ['张三', '男'];
}
 
//输出：姓名：张三，性别：男

$array = [
    ['id'=>'99', 'name'=>'九十九'],
    ['id'=>'88', 'name'=>'八十八'],
    ['id'=>'77', 'name'=>'七十七'],
];
$arr1 = array_column($array, 'name');   
//输出：array (0 => '九十九',1 => '八十八',2 => '七十七',)
$arr2 = array_column($array, 'name', 'id'); 
//输出：array (  99 => '九十九',  88 => '八十八',  77 => '七十七',)

$ids = array_column($array, 'id');
$arrayCombine = array_combine($ids, $array);
/*$arrayCombine 输出:
 array ( 
     99 => array ( 'id' => '99', 'name' => '九十九', ), 
     88 => array ( 'id' => '88', 'name' => '八十八', ), 
     77 => array ( 'id' => '77', 'name' => '七十七', ), 
 )*/

$array = array(0,1,0,2,null,1,3,4,null,0);
$array = array_values(array_unique(array_diff($array, [0, null])));	//去除0,null;去重
var_export($array);
 
/*输出：
array (
  0 => 1,
  1 => 2,
  2 => 3,
  3 => 4,
)
*/

round($x, 2);

$num = "13711111111";
$str = substr_replace($num,'****',3,4);

$array = ['a'=>'我是第一个', 'b'=>'我是第二个', 'c'=>'我是第三个', 'f' => null];
if(isset($array['a'])) {
    echo 'a存在 ';
} else {
    echo 'a不存在 ';
}

if(array_key_exists('d', $array)) {
    echo 'd存在 ';
} else {
    echo 'd不存在 ';
}

if (empty($array['f'])) {
    echo 'f不存在';
} else {
    echo 'f存在,且不为 null,0,"0",false';
}
 
//a存在 d不存在 f不存在

$distName = '南山区';
$lastChar = mb_substr($distName, -1);
if($lastChar=='区'){
    $lastChar = mb_substr($distName, 0, -1);
}
echo $lastChar;

{"eat":["大米","小麦"],"drink":["水","茶"]}

//若目录不存在则创建目录
$filePath = '../file/20900101';
if(@!file_exists($filePath)){
    mkdir($filePath, 0777, true);
    chmod($filePath, 0777);
}

$temp = [
            [ 'id' => 1, 'name' => 'name1', 'age' => 'age1', 'time' => 'time1' ],
            [ 'id' => 2, 'name' => 'name2', 'age' => 'age2', 'time' => 'time2' ]
        ];

# 清空原数据
$data = $temp;
foreach ($data as &$value){
    $value = [];
}
echo &#39;<pre class="brush:php;toolbar:false">&#39;;
print_r($data);

# 重置原数据
$data = $temp;
foreach ($data as &$value){
    $value = [
        &#39;hobby&#39; => 1
    ];
}
print_r($data);

# 追加原数据
$data = $temp;
foreach ($data as &$value){
    $value[&#39;hobby&#39;] = 1;
}
print_r($data);

Array
(
    [0] => Array
        (
        )

    [1] => Array
        (
        )

)
Array
(
    [0] => Array
        (
            [hobby] => 1
        )

    [1] => Array
        (
            [hobby] => 1
        )

)
Array
(
    [0] => Array
        (
            [id] => 1
            [name] => name1
            [age] => age1
            [time] => time1
            [hobby] => 1
        )

    [1] => Array
        (
            [id] => 2
            [name] => name2
            [age] => age2
            [time] => time2
            [hobby] => 1
        )

)

public function test() {
	$url = self::getUrl('http://www.test.com', ['id' => 3, 'other' => '好的']);
	echo $url . &#39;<br>&#39;;     //打印：http://www.test.com?id=3&other=%E5%A5%BD%E7%9A%84
	echo urldecode($url);   //打印：http://www.test.com?id=3&other=好的
}

public function getUrl($apiUrl, $param = []){
    $param = http_build_query($param);
    return $apiUrl . &#39;?&#39; . $param;
}