otras cosas de PHP
en PHP tambien hay muchas variables o funciones especiales estas son:
namespace
nombra un nombre de espacio para la clase y sus metodos
php
<?php
namespace Src\System;
class DatabaseConnector {
private $dbConnection = null;
public function __construct()
{
$host = getenv('DB_HOST');
$port = getenv('DB_PORT');
$db = getenv('DB_DATABASE');
$user = getenv('DB_USERNAME');
$pass = getenv('DB_PASS');
try {
$this->dbConnection = new \PDO(
"mysql:host=".$host.";port=".$port.";charset=utf8mb4;dbname=$db",
$user,
$pass
);
} catch (\PDOException $e) {
exit($e->getMessage());
}
}
public function getConnection()
{
return $this->dbConnection;
}
}
?><?php
namespace Src\System;
class DatabaseConnector {
private $dbConnection = null;
public function __construct()
{
$host = getenv('DB_HOST');
$port = getenv('DB_PORT');
$db = getenv('DB_DATABASE');
$user = getenv('DB_USERNAME');
$pass = getenv('DB_PASS');
try {
$this->dbConnection = new \PDO(
"mysql:host=".$host.";port=".$port.";charset=utf8mb4;dbname=$db",
$user,
$pass
);
} catch (\PDOException $e) {
exit($e->getMessage());
}
}
public function getConnection()
{
return $this->dbConnection;
}
}
?>imports
los imports en PHP son intepretados en los siguientes metodos:
include
vars.php
php
<?php
$color = 'verde';
$fruta = 'manzana';
?><?php
$color = 'verde';
$fruta = 'manzana';
?>test.php
php
<?php
echo "Una $fruta $color"; // Una
include 'vars.php';
echo "Una $fruta $color"; // Una manzana verde
?><?php
echo "Una $fruta $color"; // Una
include 'vars.php';
echo "Una $fruta $color"; // Una manzana verde
?>require
el require es usado cuando trabajamos con los modulos de composer o otro administrador de paquetes
foo1.php
php
<?php
return "foo";
?><?php
return "foo";
?>foo2.php
php
<?php
$bar = require("foo.php");
echo $bar; // equals to "foo"
?><?php
$bar = require("foo.php");
echo $bar; // equals to "foo"
?>require_once
php
<?php
define('__ROOT__', dirname(dirname(__FILE__)));
require_once(__ROOT__.'/config.php');
?>
<?php require_once('/var/www/public_html/config.php'); ?><?php
define('__ROOT__', dirname(dirname(__FILE__)));
require_once(__ROOT__.'/config.php');
?>
<?php require_once('/var/www/public_html/config.php'); ?>get, post, request, env
estas variables cuya funcion son para la captura de datos desde el html o por peticiones tipo querystring
php
<?php
$_POST['name']; // post
$_GET['text']; // get
$hostname = $_ENV['MYSQL_HOST']; // env variables
$_REQUEST_['web']; // request querystring
?><?php
$_POST['name']; // post
$_GET['text']; // get
$hostname = $_ENV['MYSQL_HOST']; // env variables
$_REQUEST_['web']; // request querystring
?>comentarios
php
<?php
// soy un comentario de linea
/*
soy un
comentario
multilinea
*/
?><?php
// soy un comentario de linea
/*
soy un
comentario
multilinea
*/
?>string interpolation
php
<?php
$a = [['derp']];
$b = $a[0];
// Works. It prints derp
echo "$b[0]";
// Doesn't work. It throws an error
echo "$b[ 0 ]";
// Works. It prints derp
echo "{$b[ 0 ]}";
// Doesn't work. It prints Array[0]
echo "$a[0][0]";
// Works. It prints derp
echo "{$a[0][0]}";
// Doesn't work. It prints { Array[0] }
echo "{ $a[0][0] }";
?><?php
$a = [['derp']];
$b = $a[0];
// Works. It prints derp
echo "$b[0]";
// Doesn't work. It throws an error
echo "$b[ 0 ]";
// Works. It prints derp
echo "{$b[ 0 ]}";
// Doesn't work. It prints Array[0]
echo "$a[0][0]";
// Works. It prints derp
echo "{$a[0][0]}";
// Doesn't work. It prints { Array[0] }
echo "{ $a[0][0] }";
?>closures
php
<?php
$param = 'John!';
function sayHello()
{
$param = 'Michael!';
$func = function() use ($param)
{
echo 'Hi, I am ' . $param;
};
$func();
}
sayHello();
?><?php
$param = 'John!';
function sayHello()
{
$param = 'Michael!';
$func = function() use ($param)
{
echo 'Hi, I am ' . $param;
};
$func();
}
sayHello();
?>