php.md

PHP

• used to serve a browser, send and receive cookies, build dynamic webpages, evaluate form data
• files must be saved as .php as opposed to .html

Syntax

• tag: <?php //text ?>
• semi-colon to end lines

Strings

• to concatenate elements, use . (as opposed to +)

Variables

• $varName = "name";

Arrays

• $arrayName = array("item0", item1");
• to access elements in the array: $arrayName[0];
• to remove elements: unset($arrayName[0]); or to remove the whole array: unset($arrayName);

if Statements

    if (value){
      //statements 
    } 

Loops

• for loops:

  for ($i=0; $i<10; $i++){
      //statements
    }

• foreach loops: to iterate through each element in an array

    foreach ($arrayName as $name){
      echo #name; 
    }

• while loops:

  while(cond){
      //statements
    }

• dowhile: executes at least once

  do{
      //statements
    }while(cond);

String Functions & More

• echo: output a string, not a function
• strlen("string"): returns the length of the string
• substr($string, starting position, number of characters to return): returns a substring
• strtoupper($string) and strtolower($string): makes string upper/lower case
• strpos($string, "a"): returns position of a letter within the string

Math Functions

• round(12.12422, 4): rounds the floating point to 4 digits after decimal
• rand(1, 10): returns a random number between 1 and 10

Array Functions

• array_push($arrayName, element): adds an element to end of array
• count($array): returns the number of elements in the array
• join(",", $array): returns the elements with "," in between

Creating Functions

function name(parameters){
      //statements
}

Classes

• Creating Classes

class className(parameters){
      public $characteristic = parameters; 
      }

• Creating Instances of Classes obj1 = new Classname();

• Accessing Properties $obj1->property;