PHP

Running

See setup and AMP notes, need the server

Basics

<?php
  //code here
  $my_name = "JJ";
  print($my_name);
    print "Hi"
?>
<div> body </div>

• dynamically typed language

• All variable names begin with a $ followed by letters digits or underscores

Printing

• echo //no return type

• print //return true always

• if you use (), only one argument

• should do $s." ".$t

Functions

• Function names are not case sensitive

• & in function def is pass by reference

• javascript scoping for functions not {}

• global declaration global $x makes it Avaliable everywhere

  <?php
  function increment(&$num) {
  // this $num is the actual parameter below
  $num++;
    print('$num in function: ' . "$num");
  }
  ?>

Strings

<?php 
  "Passwd:$password[Joe]" #double quotes allow interpolation
  $name = 'j' . 'f' #concatination
  $str = implode("^",$ar") #join in python
  $ar = explode(":",$str); #split in python
?>

Arrays

Basically dictionaries that if not set use numeric indexes

<?php
$ar = array("key1"=>"value 1", 67=>3, "a"=>10, 4=>"Hi");
$x = array();
$my_array[2] = 2006; // this is literally declaring an array
$my_array = array("Hello",2,TRUE);

$usernames = array_keys($ar);
$passwds= array_values($ar);
?>

Functions to call on arrays

• unset //entry or entire array

• count OR sizeof

• is_array

Control

• if and then like C++, switch statement

  Loops

• while, for

<?php
  foreach($array as $value) {}
  foreach($array as $key => $value){}
  for ($i = 0; $i < 10; $i++) {
    //
  }
?>

Big Project Functions

• isset($x)

• gettype($x)

Includes

include("filename")

• check

ERRORS

Do not put a space between #!/usr/local/bin/php <?php ?>