Install PHP . In my case I just downloaded window package and unzipped it into /C/php/ folder. Type /C/php/php.exe -v and get PHP 8.1.1 (cli) Get started Create file.php inside /C/php/myFolder/ with following code <?php echo "hi" ?> and execute the file by /C/php/php.exe /C/php/myFolder/file.php and got hi in the terminal Output
<?php
echo "hi\n"; # hi + new line
echo 'hi'; # \n not working in single quotes
print "hi"; # hi
var_dump('hi'); # string(2) "hi"
print_r('hi'); # hi
?>
Comment
<?php
# comment
// comment
/*
multiline
comment
*/
?>
Variable Starts with dollar sign $
<?php
$num = 5;
echo $num;
?>
Constant
<?php
define('PI', 3.1415926);
echo PI; # 3.1415926
?>
Strings Concatenation
<?php
echo "Hello "."John"."\n"."I am your robot";
# Hello John
# I am your robot
?>
Interpolation
<?php
$str = 'John';
echo "Hi, $str. How are you?"; # Hi, John. How are you?
echo "Hi, {$str}. How are you?"; # Hi, John. How are you?
echo 'Hi, '.$str. '. How are you?'; # Hi, John. How are you?
echo 'Hi, '.$str. '. How are you?'; # Hi, John. How are you?
?>
Multiline string
<?php
$information = <<<XXX
line 1
line 2
XXX;
echo $information;
# line 1
# line 2
?>
Length
<?php
echo strlen("abcd"); # 4
?>
Trim
<?php
var_dump(ltrim(" abcd ")); # string(7) "abcd "
var_dump(rtrim(" abcd ")); # string(7) " abcd"
var_dump(trim(" abcd ")); # string(4) "abcd"
?>
Uppercase, lowercase
<?php
echo strtoupper("john"); # JOHN
echo strtolower("JOHN"); # john
echo ucfirst("john"); # John
?>
Split, explode
<?php
var_dump(explode('ll', 'hello'));
/*
array(2) {
[0] => string(2) "he"
[1] => string(1) "o"
}
*/
var_dump(str_split('hello'));
/*
array(5) {
[0] => string(1) "h"
[1] => string(1) "e"
[2] => string(1) "l"
[3] => string(1) "l"
[4] => string(1) "o"
}
*/
?>
Substring
<?php
echo substr('hello', 0, 3) # hel
?>
Position
<?php
echo strpos('hello', 'e') # 2
?>
Replace
<?php
echo str_replace('e', 'a', 'hello') # hallo
?>
Operators Math
<?php
echo (5 + 2); # 7
echo (5 - 2); # 3
echo (5 * 2); # 10
echo (5 / 2); # 2.5
echo (integer) (5 / 2); # 2
echo (5 % 2); # 1
?>
Comparison
== === != !== < > <= >=
Logical
&& || !
Data types
<?php
echo gettype(5); # integer
echo gettype(5.123); # double
echo gettype('hi'); # string
echo gettype(true); # boolean
echo gettype([1, 2, 3]); # array
echo gettype(NULL); # NULL
class Car {
public $color;
public $model;
public function __construct($color, $model) {
$this->color = $color;
$this->model = $model;
}
public function message() {
return "My car is a " . $this->color . " " . $this->model . "!";
}
}
$myCar = new Car("black", "Volvo");
echo $myCar -> message();
echo gettype($myCar); # object
?>
Type conversion
<?php
echo (integer) (5.123); # 5
echo (integer) ("66 times"); # 66
$decimalNum = 2.3456;
printf ("decimal num = %.2f </br>", $decimalNum);
// Other conversion codes
// b : integer to binary
// c : integer to character
// d : integer to decimal
// f : double to float
// o : integer to octal
// s : string to string
// x : integer to hexadecimal
?>
Reference
<?php
$num = 5;
$refToNum = &$num;
$num = 100;
echo $refToNum; # 100
?>
Conditionals If-elseif-else
<?php
if(5 == 10) {
echo "5 = 10";
} elseif(((5 > 10) && (10 > 20)) || (!true === true)) {
echo "(5 > 10) && (10 > 20))";
} else {
echo "all above was false";
}
# all above was false
?>
Ternary operator
<?php
$num = 15 > 10 ? 'bigger' : 'smaller';
echo $num; # bigger
?>
Switch statement
<?php
$name = 'John';
switch($name) {
case "Derek":
echo "Hello Derek";
break;
case "John":
echo "Hello John";
break;
default:
echo "Hello unknown customer";
break;
}
?>
Loops for
<?php
for ($num = 1; $num <= 10; $num++) {
echo $num.', '; # 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,
}
?>
break, continue
<?php
for ($num = 1; $num <= 10; $num++) {
if($num === 9) break; # or exit();
if($num === 5) continue;
echo $num.', '; # 1, 2, 3, 4, 6, 7, 8,
}
?>
while
<?php
$num = 0;
while ($num < 5) {
echo ++$num . ', '; # 1, 2, 3, 4, 5,
}
?>
PHP cheat-sheet on every property and method. Arrays Indexed array
<?php
$arr = array(1, 2, 3, 4, 5);
echo $arr[0]; # 1
$arr = [1, 2, 3, 4, 5];
echo $arr[0]; # 1
?>
For each
<?php
$arr = [1, 2, 3, 4, 5];
foreach($arr as $num) {
echo $num; # 12345
}
?>
Associative array (key-value pairs)
<?php
$arr = array('name' => 'John', 'sex' => 'male', 'age' => 35);
foreach($arr as $key => $value) {
echo $key.' - '.$value."\n";
}
# name - John
# sex - male
# age - 35
echo $arr['name']; # John
$arr['name'] = 'Jane';
echo $arr['name']; # Jane
?>
Add, modify
<?php
$arr = [1, 2, 3];
$arr[2] = 10;
$arr[3] = 100;
print_r($arr); # John
/*
Array
(
[0] => 1
[1] => 2
[2] => 10
[3] => 100
)
*/
?>
Combine
<?php
$arr1 = array('name' => 'John');
$arr2 = array('name' => 'Anton', 'sex' => 'male', 'age' => 36, 'isHappy' => "yes");
$arr3 = $arr1 + $arr2;
print_r($arr3);
/*
Array
(
[name] => John
[sex] => male
[age] => 36
[isHappy] => yes
)
*/
?>
Compare Compares by values, not by reference, like in JS
<?php
$arr1 = [1, 2, 3];
$arr2 = [1, 2, 3];
var_dump($arr1 === $arr2); # bool(true)
?>
Sort
<?php
// sort strings
$arr = ['a', 'c', 'e', 'b', 'd'];
sort($arr, SORT_STRING);
print_r($arr);
/*
Array
(
[0] => a
[1] => b
[2] => c
[3] => d
[4] => e
)
*/
// sort numbers
$arr = [1, 5, 2, 4, 3];
var_dump(sort($arr, SORT_NUMERIC)); # bool(true)
print_r($arr);
/*
Array
(
[0] => 1
[1] => 2
[2] => 3
[3] => 4
[4] => 5
)
*/
// reverse
rsort($arr, SORT_NUMERIC);
print_r($arr);
/*
Array
(
[0] => 5
[1] => 4
[2] => 3
[3] => 2
[4] => 1
)
*/
// sort with keys
asort($arr);
print_r($arr);
/*
Array
(
[0] => 1
[2] => 2
[4] => 3
[3] => 4
[1] => 5
)
*/
// sort by keys
ksort($arr);
print_r($arr);
/*
Array
(
[0] => 1
[1] => 5
[2] => 2
[3] => 4
[4] => 3
)
*/
?>
Map
<?php
$func = function($val) {
return $val * 2;
};
$arr = [1, 2, 3];
print_r(array_map($func, $arr));
/*
Array
(
[0] => 2
[1] => 4
[2] => 6
)
*/
?>
Filter
<?php
function odd($var) {
return $var & 1;
}
$arr1 = ['a' => 1, 'b' => 2, 'c' => 3, 'd' => 4, 'e' => 5];
$arr2 = [6, 7, 8, 9, 10, 11, 12];
print_r(array_filter($arr1, "odd"));
# Array ( [a] => 1 [c] => 3 [e] => 5 )
print_r(array_filter($arr2, "odd"));
# Array ( [1] => 7 [3] => 9 [5] => 11 )
?>
Function Function declaration
<?php
function sum($num1, $num2) {
return $num1 + $num2;
}
echo sum(1,2) # 3
?>
Function expression
<?php
$sum = function($num1, $num2) {
return $num1 + $num2;
};
echo $sum(1, 2); # 3
?>
Arrow function (lambda)
<?php
$sum = fn($num1, $num2) => $num1 + $num2;
echo $sum(1,2) # 3
?>
File Create, write
<?php
$currentFolder = __DIR__; # C:\php\myFolder
$myfile = fopen($currentFolder."\file.txt", "w") or die("Unable to open file!");
fwrite($myfile, "Line 1\n");
fwrite($myfile, "Line 2\n");
fclose($myfile);
?>
Read
<?php
$currentFolder = __DIR__; # C:\php\myFolder
$myfile = fopen($currentFolder."\file.txt", "r") or die("Unable to open file!");
echo fread($myfile,filesize($currentFolder."\file.txt"));
fclose($myfile);
# Line 1
# Line 2
?>
PHP cheat-sheet on every property and method.