DAY 1

• boolean = true or false
• int = integer
• float = fraction
• string = text, in quotes
• resource = external (not native to PHP) resource
• $variablename

Associative arrays

• $myArray = array (“keyname1″=>”value1″, “keyname2″ =>”value2″);
• If no key name is provided, the default is 0, 1, 2… etc.
• [square brackets are used to ACCESS array contents]
• (normal brackets are used to SET UP functions and arrays)

HTML

<pre>
this will print on two
lines, even without a br tag
</pre>

Examples

$x = $x + 1;
//equals
x ++;

$n = 3;
echo $n * $n- -;
// (ignore spaces between minus symbols) equals
echo $n * ($n- -);

// two minus symbols after $n means run the line then apply (-1) to $n

$n = 3;
echo $n * – -$n;
// equals
– -$n;
echo $n*$n;

// two minus symbols before $n means apply (-1) to $n THEN run whole line.

$a = 10;
$b = $a; // SET b to value of $a (10)
$b = 20;
echo $a; //outputs 10

$a = 10;
$b = &$a; // the ‘&’ LINKS $a and $b
$b = 20;
echo $a; // outputs 20

== means are they the same VALUE?

=== means are they the same VALUE AND TYPE (e.g. integer or string)?

$array = array (); // creates an empty array

$array [] = array(‘a’,'b’); // puts array(‘a’,'b’) INTO slot 0 of $array[]

$a = array(1,2,3);
$b = array(‘a’=>1,’b'=>2,’c'=>3);
$c = array(1,2,3);

$a+$b will produce array(1,2,3,1,2,3)

$a+$c will produce array(1,2,3) //as values and keys are the same

• isset checks if a key has ANY value
• array_key_exists checks if a key exists
• in_array checks is a CERTAIN VALUE exists
• array_flip swaps keys for their values
• array_reverse reverses ORDER of values – keys remain in place

e.g.
$a = array(‘a’=NULL);
echo isset($a['a']) //will FAIL because NULL means no value
echo array_key_exists(‘a’,$a) //will PASS (because ‘a’ exists)
echo in_array(2,$a) //will FAIL because there is no ’2′ value in $a

DAY 2

sort($array);
//will destroy keys and put values in alphabetical order, assigned to default numerical keys, i.e. 0,1,2…

asort($array);
//keeps keys and arranges in order of values alphabetically

Ascending order (A->Z) is default. Descending order uses rsort() and arsort().

sort would do 1,20,11,2,3 etc.
natsort realises that 10 is bigger than 9, so does 1,2,3…8,9,10,11….

ksort //puts in alphabetical order by KEY
krsort //orders alphabetically in descending order by key

shuffle //puts values in random order (keys destroyed and reassigned as 0,1,2…)

array_keys() //puts KEYS into their own array, in the order they are already in (doesn’t sort alphabetically).

array_push($stack,’foo’,'bar’); //adds foo, then bar, to array $stack.

array_diff($a,$b) //produces any VALUES in $a which are NOT in $b. Keys are not compared, but are KEPT.

array_intersect($a,$b) //returns ‘duplicate’ values (that are found in $a AND $b), irrelevant of key, but key from $a is kept. If two ‘x’ values are found in $a and one is found in $b, both values from $a are returned.

If using $something in a string, use double quotes. Only use single quotes for plain text to be output literally (not processed).

PHP_EOL //end of line

error_reporting(0); //returns all errors. Other numbers limit error messages to certain ones.

Comparing strings

if(strcmp($str,”hello”)===0);

In a form, if you set the name of multiple items to something[], this tells PHP they are all in the same array.

setcookie(“filename_of_cookie”,”content_of_cookie”); //creates cookie

setcookie(“filename_of_cookie”,false); //deletes cookie

DAY 3

rand(0,100); //gives a random number between 0 and 100

mysql_fetch_row //automatically repeats through all rows

mysql_connect(host,username,password);

mysql_list_dbs

Applications used: database browser – Navicat. mySQL Administrator. XAMPP Control Panel.

On navicat, where it shows a lock on a folder, it’s THAT ONE that has some privileges ALLOWED. No lock means NO privileges at all for that user have been given.

$_GET gets info from the URL.

echo “<form name=\”search Form\”action=\”search.php\”method=\”get\”>”;

// The ‘get’ here, puts whatever is input, into the URL.

echo “<select name=\”mysearch\”>”;
//mysearch is put into ULR e.g. http://www.something.com?mysearch=input