diff options
Diffstat (limited to 'php.html.markdown')
| -rw-r--r-- | php.html.markdown | 27 |
1 files changed, 19 insertions, 8 deletions
diff --git a/php.html.markdown b/php.html.markdown index 40c9dd01..1ef52f68 100644 --- a/php.html.markdown +++ b/php.html.markdown @@ -34,6 +34,7 @@ echo "World\n"; // Prints "World" with a line break ?> Hello World Again! <?php +// That is because historically PHP started as a Template engine /************************************ @@ -41,12 +42,15 @@ Hello World Again! */ // Variables begin with the $ symbol. -// A valid variable name starts with a letter or underscore, +// A valid variable name starts with a letter or an underscore, // followed by any number of letters, numbers, or underscores. +// You don't have to (and cannot) declare variables. +// Once you assign a value, PHP will create the variable with the right type. + // Boolean values are case-insensitive $boolean = true; // or TRUE or True -$boolean = false; // or FALSE or False +$boolean = FALSE; // or false or False // Integers $int1 = 12; // => 12 @@ -88,9 +92,10 @@ $escaped = "This contains a \t tab character."; $unescaped = 'This just contains a slash and a t: \t'; // Enclose a variable in curly braces if needed -$apples = "I have {$number} apples to eat."; -$oranges = "I have ${number} oranges to eat."; -$money = "I have $${number} in the bank."; +$number = 23; +$apples = "I have {$number} apples to eat."; // => I have 23 apples to eat. +$oranges = "I have ${number} oranges to eat."; // => I have 23 oranges to eat. +$money = "I have $${number} in the bank."; // => I have $23 in the bank. // Since PHP 5.3, nowdocs can be used for uninterpolated multi-liners $nowdoc = <<<'END' @@ -105,7 +110,7 @@ $sgl_quotes END; // String concatenation is done with . -echo 'This string ' . 'is concatenated'; +echo 'This string ' . 'is concatenated'; // Returns 'This string is concatenated' // Strings can be passed in as parameters to echo echo 'Multiple', 'Parameters', 'Valid'; // Returns 'MultipleParametersValid' @@ -289,7 +294,7 @@ if (false) { print (false ? 'Does not get printed' : 'Does'); // ternary shortcut operator since PHP 5.3 -// equivalent of "$x ? $x : 'Does'"" +// equivalent of "$x ? $x : 'Does'" $x = false; print($x ?: 'Does'); @@ -439,7 +444,7 @@ $bar('C'); // Prints "A - B - C" // You can call named functions using strings $function_name = 'add'; echo $function_name(1, 2); // => 3 -// Useful for programatically determining which function to run. +// Useful for programmatically determining which function to run. // Or, use call_user_func(callable $callback [, $parameter [, ... ]]); @@ -587,6 +592,12 @@ echo $my_class->property; // => "public" echo $my_class->instanceProp; // => "An instance property" $my_class->myMethod(); // => "MyClass" +// Nullsafe operators since PHP 8 +// You can use this when you're unsure if the abstraction of $my_class contains has a property/method +// it can be used in conjunction with the nullish coalesce operator to ensure proper value +echo $my_class->invalid_property // An error is thrown +echo $my_class?->invalid_property // => NULL +echo $my_class?->invalid_property ?? "public" // => "public" // Extend classes using "extends" class MyOtherClass extends MyClass |