PHP Cheatsheet

Simple php cheatsheet for quick reference and fast learning and guidance.

Hello world ! in PHP

<?php
//simple comment
echo "Hello World !";
?> 

Variables

<?php
$first_name= "Rose"; //variables start with dollar sign.
$sec_name= 01;       //numbers don't need quotes unlike the case of strings
?>

Mathematical Operators

+ //addition
- //subtraction
* //multiplication
/ //division
% //modulus
** exponent

Comparison Operators

==     //equal to 
!=     //not equal to
<>     //not equal to
!==    // not identical
>      // greater than
<      // less than
>=     // greater than or equal to 
<=     // less than or equal to 

Assignment Operators

=   //basic assignment 
+=     //addition
-=     //subtraction
*=    //multiplication
/=      //division
%=      //modulus

Increment Operators

++$variable     //pre increment
--$variable     //pre decrement
$variable++     //post increment
$variable--    // post decrement

Logical Operators

and    //true if both are true 
or    //true if only one is true
Xor   //true if either are true but not both are true
&&   //true if both are true
||   //true if one is true
!    // true if it is not true

IF statement

<?php
if (cond) {
//run this
}

Example

if(2>1){
echo "let me run please! ";
}
?>

If else statement

<?php
if (condition) {
// do something 
}
elseif (condition) {
// do something 
} 
else {
// do something
} ?>

Example:

<?php
if ($variable > 100) {
echo "Your variable is greater than 100";
} 
elseif ($variable == 150) {
Echo "Your variable is 150!";
} 
else {
"Your number is less than 100";
}
?>

Arrays

<?php
// Numeric Array
$my_array = array("titanic", "shine", "royalcarribian", "oasesoftheseas");
echo $my_var[0]; // echoes out titanic 
?>

<?php
// Associative Arrays
$ages = array("titanic"=>"39", "rose"=>"18", "flower"=>"29");
echo $ages["titanic"]; // echoes out 39 
?>

for loop

<?php
for ($count = 1; $count < 10; $count++){
echo $count;
}
?>

while loop

<?php
$count = 0;
while ($count < 10) {
echo $count;
$count++;
}
?>

Random Numbers

<?php
echo rand(1,50); // creates random number between 1 and 50
?>

Functions

<?php
function names($names) {
echo "Hello, my name is " . $names;
}
namer("Jack"); // calls the function
?>

Include Function

<?php
Include('titanic.php');
?>

Require once function

<?php
require_once('jackrose.php');
?>

Strings

<?php
$variable = "Unfulfilled love story";
str_replace("Unfulfilled", "Complete", $variable); // replace Unfulfilled with Complete
echo strtoupper($variable); // Capitalize all letters
echo ucwords($variable); // Capitalize first letter of all words
echo strtolower($variable); // Lowercase all letters
echo lcfirst($variable); // Lowercase only first word
?>

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