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Merged PHP review from emarref

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Adam 2013-06-29 20:25:21 -07:00
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@ -10,6 +10,8 @@ This document describes PHP 5+.
```php
<?php // PHP code must be enclosed with <?php ? > tags
// If your php file only contains PHP code, it is best practise to omit the php closing tag.
// Two forward slashes start a one-line comment.
# So will a hash (aka pound symbol) but // is more common
@ -23,7 +25,7 @@ This document describes PHP 5+.
print('Hello '); // Prints "Hello " with no line break
// () are optional for print and echo
echo 'World\n'; // Prints "World" with a line break
echo "World\n"; // Prints "World" with a line break
// (all statements must end with a semicolon)
// Anything outside <?php tags is echoed automatically
@ -40,13 +42,13 @@ echo 'World\n'; // Prints "World" with a line break
// followed by any number of letters, numbers, or underscores.
// Boolean values are case-insensitive
$boolean = true; // or TRUE or True
$boolean = true; // or TRUE or True
$boolean = false; // or FALSE or False
// Integers
$int1 = 19; // => 19
$int2 = -19; // => -19
$int3 = 019; // => 15 (a leading 0 denotes an octal number)
$int1 = 19; // => 19
$int2 = -19; // => -19
$int3 = 019; // => 15 (a leading 0 denotes an octal number)
$int4 = 0x0F; // => 15 (a leading 0x denotes a hex literal)
// Floats (aka doubles)
@ -55,26 +57,26 @@ $float = 1.2e3;
$float = 7E-10;
// Arithmetic
$sum = 1 + 1; // 2
$sum = 1 + 1; // 2
$difference = 2 - 1; // 1
$product = 2 * 2; // 4
$quotient = 2 / 1; // 2
$product = 2 * 2; // 4
$quotient = 2 / 1; // 2
// Shorthand arithmetic
$number = 0;
$number += 1; // Add 1 to $number
echo $number++; // Prints 1 (increments after evaluation)
echo ++$number; // Prints 3 (increments before evalutation)
$number += 1; // Increment $number by 1
echo $number++; // Prints 1 (increments after evaluation)
echo ++$number; // Prints 3 (increments before evalutation)
$number /= $float; // Divide and assign the quotient to $number
// Strings should be enclosed in single quotes;
$sgl_quotes = '$String'; // => '$String'
// Avoid using double quotes except to embed other variables
$dbl_quotes = "This is a $sgl_quotes."; // => 'This is a $String'
$dbl_quotes = "This is a $sgl_quotes."; // => 'This is a $String.'
// Special characters are only escaped in double quotes
$escaped = "This contains a \t tab character.";
$escaped = "This contains a \t tab character.";
$unescaped = 'This just contains a slash and a t: \t';
// Enclose a variable in curly braces if needed
@ -110,7 +112,7 @@ $associative = array('One' => 1, 'Two' => 2, 'Three' => 3);
// PHP 5.4 introduced a new syntax
$associative = ['One' => 1, 'Two' => 2, 'Three' => 3];
echo $associative['One']; // prints "1"
echo $associative['One']; // prints 1
// List literals implicitly assign integer keys
$array = ['One', 'Two', 'Three'];
@ -133,8 +135,8 @@ print 'Hello World!'; // So is print
$paragraph = 'paragraph';
echo 100;
echo $paragraph;
echo 100; // Echo scalar variables directly
echo $paragraph; // or variables
// If short open tags are configured, or your PHP version is
// 5.4.0 or greater, you can use the short echo syntax
@ -144,10 +146,11 @@ echo $paragraph;
$x = 1;
$y = 2;
$x = $y; // A now contains the same value sa $y
$x = $y; // $x now contains the same value as $y
$z = &$y;
// $x now contains a reference to $y. Changing the value of
// $x will change the value of $y also, and vice-versa.
// $z now contains a reference to $y. Changing the value of
// $z will change the value of $y also, and vice-versa.
// $x will remain unchanged as the original value of $y
echo $x; // => 2
echo $z; // => 2
@ -216,7 +219,7 @@ if (true) {
}
if (false) {
print "I don't";
print 'I don\'t';
} else {
print 'I get printed';
}
@ -251,7 +254,7 @@ This is displayed otherwise.
switch ($x) {
case '0':
print 'Switch does type coercion';
break; // You must include a break, or you will fall through
break; // You must include a break, or you will fall through to cases 'two' and 'three'
case 'two':
case 'three':
// Do something if $variable is either 'two' or 'three'
@ -276,16 +279,16 @@ do {
echo "\n";
for ($x = 0; $x < 10; $x++) {
echo $x; // Will echo 0 - 9
}// Prints "0123456789"
echo $x;
} // Prints "0123456789"
echo "\n";
$wheels = ['bicycle' => 2, 'car' => 4];
// Foreach loops can iterate over arrays
foreach ($wheels as $wheel_count){
echo "$wheel_count";
foreach ($wheels as $wheel_count) {
echo $wheel_count;
} // Prints "24"
echo "\n";
@ -303,9 +306,9 @@ while ($i < 5) {
break; // Exit out of the while loop
}
echo $i++;
}// Prints "012"
} // Prints "012"
for($i = 0; $i < 5; $i++){
for ($i = 0; $i < 5; $i++) {
if ($i === 3) {
continue; // Skip this iteration of the loop
}
@ -318,7 +321,7 @@ for($i = 0; $i < 5; $i++){
*/
// Define a function with "function":
function my_function() {
function my_function () {
return 'Hello';
}
@ -327,7 +330,7 @@ echo my_function(); // => "Hello"
// A valid function name starts with a letter or underscore, followed by any
// number of letters, numbers, or underscores.
function add($x, $y = 1) { // $y is optional, and defaults to 2
function add ($x, $y = 1) { // $y is optional and defaults to 1
$result = $x + $y;
return $result;
}
@ -339,7 +342,7 @@ echo add(4, 2); // => 6
// print $result; // Gives a warning.
// Since PHP 5.3 you can declare anonymous functions;
$inc = function($x){
$inc = function ($x) {
return $x + 1;
};
@ -358,78 +361,92 @@ function bar ($x, $y) {
}
$bar = bar('A', 'B');
$bar('C');
$bar('C'); // Prints "A - B - C"
// You can call named functions using strings
$function_name = 'add';
echo $function_name(1, 2); // => 3
// But, you should probably use anonymous functions instead.
// Useful for programatically determining which function to run.
// Alternatively, use call_user_func(callable $callback [, mixed $parameter [, mixed $... ]]);
/********************************
* Classes
*/
//Classes are defined with the class keyword
// Classes are defined with the class keyword
class MyClass {
const MY_CONST = 'value'; // A constant
static $staticVar = 'static';
public $property = 'public'; // Properties must declare their visibility
private $privprop = 'private'; // Accessible within the class only
protected $protprop = 'protected'; // Accessible within the class and subclasses
class MyClass
{
const MY_CONST = 'value'; // A constant
static $staticVar = 'static';
// Properties must declare their visibility
public $property = 'public';
public $instanceProp;
protected $protProp = 'protected'; // Accessible within the class and subclasses
private $privProp = 'private'; // Accessible within the class only
// Create a constructor with __construct
public function __construct($instanceProp){
public function __construct($instanceProp) {
// Access instance variables with $this
$this->instanceProp = $instanceProp;
}
// Methods are declared as functions inside a class
public function myMethod() {
print "MyClass";
public function myMethod()
{
print 'MyClass';
}
final function youCannotOverrideMe() {
final function youCannotOverrideMe()
{
}
public static function myStaticMethod() {
print "I am static";
public static function myStaticMethod()
{
print 'I am static';
}
}
echo MyClass::MY_CONST; // Outputs "value";
echo MyClass::$staticVar; // Outputs 'static';
MyClass::myStaticMethod(); // Outputs "I am static";
echo MyClass::MY_CONST; // Outputs 'value';
echo MyClass::$staticVar; // Outputs 'static';
MyClass::myStaticMethod(); // Outputs 'I am static';
// Access class members using ->.
$my_class = new MyClass("An instance property"); // The parentheses are optional.
echo $my_class->property; // => "public"
// Access class members using ->
$my_class = new MyClass('An instance property'); // The parentheses are optional if not passing in an argument.
echo $my_class->property; // => "public"
echo $my_class->instanceProp; // => "An instance property"
$my_class->myMethod(); // => "MyClass"
$my_class->myMethod(); // => "MyClass"
// Extend classes using "extends"
class MyOtherClass extends MyClass{
function printProtectedProperty(){
echo $this->protprop;
class MyOtherClass extends MyClass
{
function printProtectedProperty()
{
echo $this->protProp;
}
// Override a method
function myMethod() {
function myMethod()
{
parent::myMethod();
print " > MyOtherClass";
print ' > MyOtherClass';
}
}
$my_other_class = new MyOtherClass("Instance prop");
$my_other_class = new MyOtherClass('Instance prop');
$my_other_class->printProtectedProperty(); // => Prints "protected"
$my_other_class->myMethod(); // Prints "MyClass > MyOtherClass"
$my_other_class->myMethod(); // Prints "MyClass > MyOtherClass"
final class YouCannotExtendMe {
final class YouCannotExtendMe
{
}
// You can use "magic methods" to create getters and setters
class MyMapClass {
class MyMapClass
{
private $property;
public function __get($key)
@ -463,16 +480,19 @@ interface InterfaceTwo
abstract class MyAbstractClass implements InterfaceOne
{
public $x = "doSomething";
public $x = 'doSomething';
}
class MyConcreteClass extends MyAbstractClass implements InterfaceTwo
{
public function doSomething(){
public function doSomething()
{
echo $x;
}
public function doSomethingElse(){
echo "doSomethingElse";
public function doSomethingElse()
{
echo 'doSomethingElse';
}
}
@ -480,11 +500,14 @@ class MyConcreteClass extends MyAbstractClass implements InterfaceTwo
// Classes can implement more than one interface
class SomeOtherClass implements InterfaceOne, InterfaceTwo
{
public function doSomething(){
echo "doSomething";
public function doSomething()
{
echo 'doSomething';
}
public function doSomethingElse(){
echo "doSomethingElse";
public function doSomethingElse()
{
echo 'doSomethingElse';
}
}
@ -493,12 +516,13 @@ class SomeOtherClass implements InterfaceOne, InterfaceTwo
* Traits
*/
//Traits are available since PHP 5.4.0 and are declared using the trait keyword.
// Traits are available since PHP 5.4.0 and are declared using the trait keyword.
trait MyTrait {
trait MyTrait
{
public function myTraitMethod()
{
print "I have MyTrait";
print 'I have MyTrait';
}
}
@ -566,3 +590,5 @@ Visit the [official PHP documentation](http://www.php.net/manual/) for reference
If you're interested in up-to-date best practices, visit [PHP The Right Way](http://www.phptherightway.com/).
If you're coming from a language with good package management, check out [Composer](http://getcomposer.org/).
For common standards, visit the PHP Framework Interoperability Group's [PSR standards](https://github.com/php-fig/fig-standards).