General
Tools
- phpDocumentor.
- EasyPHP – To setup a local WAMP server.
- Laravel – PHP framework.
- CodeIgniter – PHP framework.
- PHPUnit – For unit testing.
News
See Also
- Hack – A version of PHP written by Facebook.
- HHVM – A PHP server meant to run Hack apps.
Know This
- PHP code goes between delimiters: <?php and ?>
- Output string: echo “My string”;
- Concatenation: . (e.g. “Hello” . “!” gives “Hello!”)
- All variables in PHP start with a $
- Add a semicolon at the end of each statement.
- x++ is shorthand for x+1
- Comments: // or multi-line: /* */
- Comparison Operators:
- >
- <
- <=
- >= Greater than or equal to
- == Equal to
- != Not equal to
- Conditional Statement:
- If:
- If (condition) { statement; }
- Else:
- If (condition) { statement; } else { statement; }
- Else If:
- If (condition) { statement; } elseif (condition) { statement } else { statement }
- Switch:
- switch (variable) { case 1: statement; break; case 2: statement; break; default: statement; }
- If:
- Arrays
- $array = array(“Blue”, “Orange”, “Green”);
- Each item in an array is numbered, starting on the left with 0.
- Use brackets to access an item at a specific position in an array, e.g. $array[1]
- Alternatively one can use {}. e.g. $array{1}
- To set an element in an array: $array[1] = newvalue
- To remove an element from an array use unset: unset($array[1]).
- Loops
- For
- for (start_of_loop; end_of_loop; increment_loop)
- ex.: for (x=1; x<10; x++) { command; }
- While
- while (condition) { code }
- ex.: while (x < 10) { x++; }
- Alternatively, one can use while (cond): code endwhile;
- Do While
- Will execute at least once
- do { code } while (condition);
- ex.: do { x+1 } while (x < 1);
- Foreach
- foreach (list_of_items as item) { code }
- foreach ($numbers as $item) { echo $item; }
- For
Functions
- array-merge()
- array_shift() – Takes the first value in an array out of the array and returns it.
- defined() – Checks whether a given constant exists.
- explode() – Used to create an array from a string.
- mt_rand() – Uses Mersenne Twister (mt_) to more quickly generate a random number.
- strlen()
- str_replace() – Replaces matching values found in a string with a given value.
- str_ireplace() is case-insensitive.
- Why are there leading underscores in some function names?
Operators
- ? – ternary (aka conditional) operator
- ex.: $param=isset($_GET[‘param’]) ? $_GET[‘param’] : ‘default’;
- If the first parameter is true, use its result; otherwise if second is true; use its result; else use third.
- Leaving out middle operand is supported in PHP 5.3+, middle operand above is “$_GET[‘param’]. Without middle operand looks like: $result = $x ?: ‘default’;
- :: – scope resolution (aka paamayim nekudotayim) operator
- Used when one wants to reference a specific instance of a function.
Terms
- static
- scope resolution operator
Old Code
- &$this – See Tom J. Nowell’s article of the same name. Also this and this question on Stackoverflow.
Further Reading
- Stackoverflow