PHP语法小结

echo $name?:'NO';//输出本身的话，可以省略！

echo $name??'NO';//NO

@(9/0)//不会报错

$temp=<<<tem
<h1 style="color: #e01">这是一段临时HTML模板</h1>
<h5 style="color: #00b3ff">hhc</h5>
<script>
document.querySelector("h5").addEventListener("mouseenter",function (){
    this.style.color="#000";
})
</script>
tem;

$str="fer.com";
echo $str."=>"."hhhhc";

$sentence="my name is jqf.let's go shopping!";
echo "<hr>";
echo ucwords($sentence,'.');//My name is jqf.Let's go shopping!

//tools.php
<?php
function show(){
    return 'https://www.fintinger.xyz';
}

//1.php
<?php
include 'tools.php';
echo show();

//2.php
include_once "1.php";
include_once "tools.php";

<?php
function sum(...$nums){
    print_r($nums);
    echo "<hr>";
    echo array_sum($nums);
}
sum(1,2,3,4,4,5,6,6,7,7,7,7);

declare(strict_types=1);
function sum(int ...$nums){
    return array_sum($nums);
}

echo sum(1,2,3,4,'5');//Fatal error

function show(int $var): string
{
    return 'hhc';
}//参数(php>5)和返回值(php>7)都有明确的类型约束

$action="fn";
function fn(){
	//do something
}
$action()//即可调用fn函数

function png()
{
    return 'png fn running...';
}

function jpg()
{
    return 'ipg fn running...';
}

$file = 'logo.png';

$action = explode('.', $file)[1];

echo function_exists($action)
    ? $action()
    : '无法处理这种格式的图片！';

$info = array('coffee', 'brown', 'caffeine');

// 列出所有变量
list($drink, $color, $power) = $info;
echo "$drink is $color and $power makes it special.\n";

$arr=[
    "age"=>"18",
    "name"=>"fin",
];
list("name"=>$name,"age"=>$age)=$arr;
echo $name;//fin

$arr=[
    "age"=>"18",
    "name"=>"fin",
];
extract($arr, EXTR_PREFIX_SAME, "wddx");//重复则覆盖，前缀为"wddx"
echo $name;//fin

foreach($arr $index=>$item){
    //可以获取索引和数组中的item
}

foreach ($arr as &$item){
    //do something(修改传址进来的数组元素)
}

/*遍历*/
array_map()
array_values()
array_keys()
array_filter()


/*判断*/
array_key_exists()
in_array()

/*合并*/
array_merge()//[originArr,newArr]
array_change_key_case() //修改key的大小写小:0/CASE_LOWER 大:1/CASE_UPPER

//递归实现多维数组key的大小写转换
<?php
$config = [
    "hOst" => "localhost",
    "POST" => 8000,
    "uSeR" => "admin",
    "cache" => [
        "hOst" => "127.0.0.1",
        "user" => [
            "namE" => "jqf",
            "token" => "qq9ad2437c622bdd38"
        ]
    ]
];
/**
 * @param array $arr
 * @param string $type
 * @return array
 */
function fin_array_change_key_case(array $arr, string $type = 'CASE_UPPER'): array
{
    $action = $type == "CASE_UPPER" ? 'strtoupper' : 'strtolower';
    foreach ($arr as $k => $v) {
        //删掉原先的
        unset($arr[$k]);
        //新的数组
        $arr[$action($k)] = is_array($v)
            ? fin_array_change_key_case($v)
            : $v;
    }
    return $arr;
}

$res = fin_array_change_key_case($config);
print_r($res);

date_default_timezone_set(timezone_identifier)

date('Y-m-d hⓜ️s');

time()
microtime(true)//true 返回浮点数 false 返回字符串

<?php
//得到函数执行时间的函数
/**测试函数执行时间
 * @param null $begin
 * @param null $end
 * @return array|float|mixed|string
 */
function runtime($begin = null, $end = null)
{
    static $cache = [];
    if (is_null($begin)) {
        return $cache;
    } elseif (is_null($end)) {
        return $cache[$begin] = microtime(true);
    } else {
        //👇🏼！！！！
        $end = $cache[$end] ?? microtime(true);
        return round($end - $cache[$begin],2);
    }
}

//测试for和while循环
$LEN=10000000;

//1.for
runtime('for');
for ($i = 0; $i < $LEN; $i++) {}
runtime('forEnd');
echo 'for循环:'.runtime('for', 'forEnd');

echo "<hr>";

//2.while
runtime('while');
$i=0;
while ($i<$LEN){$i++;};
runtime('whileEnd');
echo 'while循环:'.runtime('while', 'whileEnd');
echo "<hr>";
echo '总执行时间:'.runtime('for','whileEnd');

<?php
//date() =>填参数得到不同的结果
//getdate() =>返回数组

/*转为时间戳*/
//具体查手册
//strtotime() =>参数为str,比如"NOW","2020-04-02 10:00:00"...
//strtotime('+1 year +10 day')=>1年10天后
//strtotime('next friday')=>下个星期五

<?php

//new Date()->format()//%m月%d天%h小时,一共%a天
//new Date()->setdate()
//new Date()->diff() 获取俩时间差值
//...

//参数'P2DT2H5M'=>增加2d2h5m
//P->开始,  D->'day',  T->分割日期和时间
//配合new Date->add($interval)函数使用！！！

<?php
//preg_match(reg,str,res) =>匹配一个
//preg_match_all()=>所有

//preg_split(reg,str)=>拆分字符串，返回处理后结果

//preg_replace(reg,val_replace,str)=>替换
//preg_replace_callback(reg,fn,str)=>fn中接收$matches实现复杂逻辑

session_start();//开始
$_SESSION["web"] = "https://www.fintinger.xyz";//设置数据
print_r($_SESSION);//可以通过超全局数组获取

session_save_path("./temp");//查看或设置

//id一般在自定义session引擎的时候设置
session_name("jqf");
session_id("123");
session_start();//配置在开始之前

class FileHandle inplements SessionlandlerInterface{}

<?php


class FileHandle implements SessionHandlerInterface
{

    /**
     * @inheritDoc
     */
    public function close()
    {
        // TODO: Implement close() method.
    }

    /**
     * @inheritDoc
     */
    public function destroy($session_id)
    {
        // TODO: Implement destroy() method.
    }

    /**
     * @inheritDoc
     */
    public function gc($maxlifetime)
    {
        // TODO: Implement gc() method.
    }

    /**
     * @inheritDoc
     */
    public function open($save_path, $name)
    {
        // TODO: Implement open() method.
    }

    /**
     * @inheritDoc
     */
    public function read($session_id)
    {
        // TODO: Implement read() method.
    }

    /**
     * @inheritDoc
     */
    public function write($session_id, $session_data)
    {
        // TODO: Implement write() method.
    }

}

<?php

/**
 * Class FileHandle
 * @param $path //session储存路径
 * @param $maxlifetime //session文件过期时间
 */
class FileHandle implements SessionHandlerInterface
{

    protected $path;

    protected $maxlifetime;

    public function __construct($path = "session", $maxlifetime = "1440")
    {
        $this->path = $this->mkdir($path);
        $this->maxlifetime = $maxlifetime;
    }

    private function mkdir($path)
    {
        is_dir($path) || mkdir($path);

        return realpath($path);
    }

    public function close(): bool
    {
        return true;
    }

    public function destroy($session_id): bool
    {
        if (is_file($this->path."/".$session_id)) {
            @unlink($this->path."/".$session_id);
        }

        return true;
    }

    public function gc($maxlifetime): bool
    {
        foreach (glob($this->path."/*") as $file) {
            if (filemtime($file) + $this->maxlifetime < time()) {
                @unlink($file);
            }
        }

        return true;
    }


    public function open($path, $name): bool
    {
        return true;
    }

    public function read($session_id): string
    {
        return (string)@file_get_contents($this->path."/".$session_id);
    }

    public function write($session_id, $session_data): bool
    {
        return (bool)@file_put_contents($this->path."/".$session_id, $session_data);
    }

}

<?php
$handle=fopen("file/test.txt",'r');

//feof($handle)=>文件读取是否完毕
//while (!feof($handle)){
//    echo fread($handle,1);
//}


//fgetc($handle)=>每次读取一个字符！
while (!feof($handle)){
    echo fgetc($handle);
}


//fgets($handle)=> 每次一行！

//fgetss($handle)=>v7.3弃用，
//fgetcsv($handle,split)=>读取，并指定用什么分割开来

//文件&目录权限
//is_writable()
//is_readable()

//文件&目录检查
//file_exists()
//is_file()&is_dir()

mkdir("a/b/c",0755,true)

glob("./*")//当前路径下所有
glob("./*.php")//当前路径下的php文件
glob("{./*.php,*.txt}")//当前路径下php和txt

//GLOB_MARK =>后面补 "/"
//GLOB_NOSORT =>使用系统默认排序
//GLOB_ERR =>没有权限操作目录时，停止所有动作（默认跳过）
//GLOB_NOCHECK =>目录不存在，返回模式

//u1.php
$handle=fopen("jqf.txt","r");
flock($handle,LOCK_SH);
sleep(3);//模拟写入操作的延时
echo fread($handle,99);
flock($handle,LOCK_UN);
fclose($handle);

//u2.php
$handle = fopen("jqf.txt", "a+");
flock($handle, LOCK_EX);
fwrite($handle, '*hm');
fseek($handle, 0);
echo fread($handle, 99);
flock($handle,LOCK_UN);
fclose($handle);

//u1.php
$handle = fopen('jqf.txt', 'a+');
flock($handle, LOCK_EX);
sleep(3);
fwrite($handle, '*hm');
fseek($handle, 0);
echo fread($handle, 99);
flock($handle, LOCK_UN);
fclose($handle);

//u2.php
$handle=fopen('jqf.txt','r+');
flock($handle,LOCK_SH);
echo fread($handle,99);
flock($handle,LOCK_UN);
fclose($handle);

/**格式化获取磁盘空间大小
 * 注意数组的顺序，判断由大到小!!!!
 * @param int $total
 * @return string
 */
function space_total(int $total):string
{
    $config=[3=>'GB',2=>'MB',1=>'KB'];
    foreach ($config as $num=>$unit) {
        if ($total>pow(1024,$num)){
            return round($total/pow(1024,$num)).$unit;
        }
    }
    return $total.'B';
}

echo "<hr>";
echo '磁盘总大小：'.space_total(disk_total_space('.'));
echo "<hr>";
echo '剩余大小：'.space_total(disk_free_space('.'));

/**
 * 如果刷新页面前后不超过10s，将会一直走缓存,否则会更新缓存
 * ob_start()&ob_get_contents()可以在引入时获取引入内容
 */
$CACHE = 'file/文件缓存/file.cache.php';
$BLADE = 'file/文件缓存/file.blade.php';

if (is_file($CACHE) && filemtime($CACHE) > time() - 10) {
    echo 'is cache...';
    include $CACHE;
} else {
    ob_start();
    include $BLADE;
    $content = ob_get_contents();
    file_put_contents($CACHE, $content);
}

<?php
$db = ["host" => "localhost", "port" => 2000, "pwd" => "admin888"];
//不带true会输出符合php语法的数组
$config = var_export($db, true);

file_put_contents('file/var_export_config.php', "<?php return " . $config . ";");

/**统计目录大小
 * @param string $dir
 * @return int
 */
function dir_size(string $dir = "."): int
{
    $size = 0;
    foreach (glob($dir . "/*") as $file) {
        $size += is_file($file)?filesize($file):dir_size($file);
    }
    return $size;
}

/**递归复制整体目录
 * @param string $from
 * @param string $to
 * @return bool
 */
function copy_dir(string $from, string $to): bool
{
    !is_dir($to) && mkdir($to, 0755, true);
    foreach (glob($from . "/*") as $file) {
        $target = $to . "/" . basename($file);
        is_file($file)
            ? copy($file, $target)
            : copy_dir($file, $target);
    };
    return true;
}

/**删除多级目录
 * 千万小心！！！
 * @param string $dir
 * @return bool
 */
function del_dir(string $dir)
{
    if (!is_dir($dir)) {
        return true;
    }
    foreach (glob($dir . "/*") as $file) {
        is_file($file) ? unlink($file) : del_dir($file);
    }
    return rmdir($dir);
}

namespace foo;
use My\Full\Classname as Another;

// 下面的例子与 use My\Full\NSname as NSname 相同
use My\Full\NSname;

// 导入一个全局类
use ArrayObject;

// importing a function (PHP 5.6+)
use function My\Full\functionName;

// aliasing a function (PHP 5.6+)
use function My\Full\functionName as func;

// importing a constant (PHP 5.6+)
use const My\Full\CONSTANT;

<?php
namespace App;

spl_autoload_register(
    function ($name) {
        $file = str_replace("\\", "/", $name).".php";
        require $file;
    }
);

use App\Module\Shop\Server\Member;
Member::show();

//Autoload.php类
namespace App;

class Autoload
{
    public static function boot()
    {
        spl_autoload_register([new self, "autoload"]);//注意传参方式
    }
    public function autoload($name)
    {
        $file = str_replace("\\", "/", $name).".php";
        require $file;
    }
}

Autoload::boot();//自动调用静态方法，引入之后不需调用

//use.php
namespace App;
include "Autoload.php";
use App\Module\Shop\Server\Member;

Member::show();

composer init

"autoload":{
    "psr-4":{
    "App\\":"App"
    }
}

conposer build

class User{
    protected static $name="fin";
    public static function show(){
        return self::$name;//self 关键字表示当前对象，
    }
}
$u=new User();
echo $u->show();
echo User::show();

class Model
{
    const EXISTS_VALUE=1;
}
echo Model::EXISTS_VALUE;
$m=new Model();
echo $m::EXISTS_VALUE;

class Test
{
    public function __construct()
    {
        echo "__construct";
    }

    public function __destruct()
    {
        echo "__destruct";
    }
  /*  public function __run()
    {
        echo "__run";
    }*/
}

new Test();

class Father{
    private static $name="jqf";
    public final function show(){
        return Father::$name;
    }
}
class Child extends Father{
//    public function show(){}//Cannot override final method
}

<?php

trait Commit
{
    public function publish()
    {
        return __METHOD__;
    }
}

trait Log
{
    public function show()
    {
        return __METHOD__;
    }
}

class Topic
{
    use Commit, Log;
}

$topic = new Topic;
echo $topic->publish();
echo "<hr>";
echo $topic->show();

//类中方法名冲突，通过替换+改名解决
use Commit, Log{
    Commit::show insteadof  Log;//设置优先级
    Log::show as export;//优先级低的改名
}

use Commit{
    Commit::publish as protected;
}

error_log ( string $message [, int $message_type = 0 [, string $destination [, string $extra_headers ]]] ) : bool

//范例
<?php
function exception_handler($exception) {
  echo "Uncaught exception: " , $exception->getMessage(), "\n";
}

set_exception_handler('exception_handler');

throw new Exception('Uncaught Exception');
echo "Not Executed\n";
?>