diff options
Diffstat (limited to 'php.html.markdown')
| -rw-r--r-- | php.html.markdown | 155 | 
1 files changed, 132 insertions, 23 deletions
| diff --git a/php.html.markdown b/php.html.markdown index 39ec5aef..6944390c 100644 --- a/php.html.markdown +++ b/php.html.markdown @@ -12,7 +12,7 @@ This document describes PHP 5+.  <?php // PHP code must be enclosed with <?php tags  // If your php file only contains PHP code, it is best practice -// to omit the php closing tag. +// to omit the php closing tag to prevent accidental output.  // Two forward slashes start a one-line comment. @@ -53,6 +53,8 @@ $int1 = 12;   // => 12  $int2 = -12;  // => -12  $int3 = 012;  // => 10 (a leading 0 denotes an octal number)  $int4 = 0x0F; // => 15 (a leading 0x denotes a hex literal) +// Binary integer literals are available since PHP 5.4.0. +$int5 = 0b11111111; // 255 (a leading 0b denotes a binary number)  // Floats (aka doubles)  $float = 1.234; @@ -103,6 +105,9 @@ END;  // String concatenation is done with .  echo 'This string ' . 'is concatenated'; +// Strings can be passed in as parameters to echo +echo 'Multiple', 'Parameters', 'Valid';  // Returns 'MultipleParametersValid' +  /********************************   * Constants @@ -113,10 +118,12 @@ echo 'This string ' . 'is concatenated';  // a valid constant name starts with a letter or underscore,  // followed by any number of letters, numbers, or underscores. -define("FOO",     "something"); +define("FOO", "something"); + +// access to a constant is possible by calling the choosen name without a $ +echo FOO; // Returns 'something' +echo 'This outputs ' . FOO;  // Returns 'This ouputs something' -// access to a constant is possible by direct using the choosen name -echo 'This outputs '.FOO;  /******************************** @@ -135,12 +142,17 @@ $associative = ['One' => 1, 'Two' => 2, 'Three' => 3];  echo $associative['One']; // prints 1 +// Add an element to an associative array +$associative['Four'] = 4; +  // List literals implicitly assign integer keys  $array = ['One', 'Two', 'Three'];  echo $array[0]; // => "One"  // Add an element to the end of an array  $array[] = 'Four'; +// or +array_push($array, 'Five');  // Remove element from array  unset($array[3]); @@ -155,9 +167,9 @@ echo('Hello World!');  print('Hello World!'); // The same as echo -// echo is actually a language construct, so you can drop the parentheses. +// echo and print are language constructs too, so you can drop the parentheses  echo 'Hello World!'; -print 'Hello World!'; // So is print +print 'Hello World!';  $paragraph = 'paragraph'; @@ -215,7 +227,11 @@ assert($a !== $d);  assert(1 === '1');  assert(1 !== '1'); -// spaceship operator since PHP 7 +// 'Spaceship' operator (since PHP 7) +// Returns 0 if values on either side are equal +// Returns 1 if value on the left is greater +// Returns -1 if the value on the right is greater +  $a = 100;  $b = 1000; @@ -379,7 +395,7 @@ for ($i = 0; $i < 5; $i++) {  // Define a function with "function":  function my_function () { -  return 'Hello'; +    return 'Hello';  }  echo my_function(); // => "Hello" @@ -388,8 +404,8 @@ echo my_function(); // => "Hello"  // number of letters, numbers, or underscores.  function add ($x, $y = 1) { // $y is optional and defaults to 1 -  $result = $x + $y; -  return $result; +    $result = $x + $y; +    return $result;  }  echo add(4); // => 5 @@ -400,21 +416,21 @@ echo add(4, 2); // => 6  // Since PHP 5.3 you can declare anonymous functions;  $inc = function ($x) { -  return $x + 1; +    return $x + 1;  };  echo $inc(2); // => 3  function foo ($x, $y, $z) { -  echo "$x - $y - $z"; +    echo "$x - $y - $z";  }  // Functions can return functions  function bar ($x, $y) { -  // Use 'use' to bring in outside variables -  return function ($z) use ($x, $y) { -    foo($x, $y, $z); -  }; +    // Use 'use' to bring in outside variables +    return function ($z) use ($x, $y) { +        foo($x, $y, $z); +    };  }  $bar = bar('A', 'B'); @@ -426,6 +442,31 @@ echo $function_name(1, 2); // => 3  // Useful for programatically determining which function to run.  // Or, use call_user_func(callable $callback [, $parameter [, ... ]]); + +// You can get the all the parameters passed to a function +function parameters() { +    $numargs = func_num_args(); +    if ($numargs > 0) { +        echo func_get_arg(0) . ' | '; +    } +    $args_array = func_get_args(); +    foreach ($args_array as $key => $arg) { +        echo $key . ' - ' . $arg . ' | '; +    } +} + +parameters('Hello', 'World'); // Hello | 0 - Hello | 1 - World | + +// Since PHP 5.6 you can get a variable number of arguments +function variable($word, ...$list) { +	echo $word . " || "; +	foreach ($list as $item) { +		echo $item . ' | '; +	} +} + +variable("Separate", "Hello", "World") // Separate || Hello | World |  +  /********************************   * Includes   */ @@ -693,6 +734,74 @@ use My\Namespace as SomeOtherNamespace;  $cls = new SomeOtherNamespace\MyClass(); + +/********************** +* Late Static Binding +* +*/ + +class ParentClass { +    public static function who() { +        echo "I'm a " . __CLASS__ . "\n"; +    } +    public static function test() { +        // self references the class the method is defined within +        self::who(); +        // static references the class the method was invoked on +        static::who(); +    } +} + +ParentClass::test(); +/* +I'm a ParentClass +I'm a ParentClass +*/ + +class ChildClass extends ParentClass { +    public static function who() { +        echo "But I'm " . __CLASS__ . "\n"; +    } +} + +ChildClass::test(); +/* +I'm a ParentClass +But I'm ChildClass +*/ + +/********************** +*  Magic constants +*   +*/ + +// Get current class name. Must be used inside a class declaration. +echo "Current class name is " . __CLASS__; + +// Get full path directory of a file +echo "Current directory is " . __DIR__; + +    // Typical usage +    require __DIR__ . '/vendor/autoload.php'; + +// Get full path of a file +echo "Current file path is " . __FILE__; + +// Get current function name +echo "Current function name is " . __FUNCTION__; + +// Get current line number +echo "Current line number is " . __LINE__; + +// Get the name of the current method. Only returns a value when used inside a trait or object declaration. +echo "Current method is " . __METHOD__; + +// Get the name of the current namespace +echo "Current namespace is " . __NAMESPACE__; + +// Get the name of the current trait. Only returns a value when used inside a trait or object declaration. +echo "Current namespace is " . __TRAIT__; +  /**********************  *  Error Handling  *   @@ -702,15 +811,15 @@ $cls = new SomeOtherNamespace\MyClass();  try {      // Do something -} catch ( Exception $e) { +} catch (Exception $e) {      // Handle exception  }  // When using try catch blocks in a namespaced enviroment use the following -try {  +try {      // Do something -} catch (\Exception $e) {  +} catch (\Exception $e) {      // Handle exception  } @@ -719,13 +828,13 @@ try {  class MyException extends Exception {}  try { -     -    $condition = true;  -     + +    $condition = true; +      if ($condition) {          throw new MyException('Something just happend');      } -     +  } catch (MyException $e) {      // Handle my exception  } | 
