PHP Tips for certification - OdW13

.:PHP:.
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web interpreted language
Auto. memory management
Weakly typed
Highly dynamic
Light and efficient
Cross-plateform

PHP gotcha !
 Highly dynamic language
 Borrows some concepts from perl / C

 Lots of weird behaviors
 To be known

 Certification exam can fool you with such behaviors

PHP gotcha

if (DONT_EXIST) {
echo "true";
} else {
echo "false";
}

PHP gotcha revealed
if (DONT_EXIST) {
echo "true";
} else {
echo "false";
}

if ("DONT_EXIST")

if (true)

PHP gotcha

$text = "foo and bar";
if (strpos($text, "foo") {
echo "foo is here";
} else {
echo "foo is not here";
}

PHP gotcha

echo (true?'true':false?'t':'f');

PHP gotcha revealed

echo (true?'true':false?'t':'f');

echo ( (true?'true':false) ?'t':'f' );

PHP gotcha

$a = 'foobar';
$a[10] = 'foo';
var_dump($a);

PHP gotcha revealed

$a = 'foobar';
$a[10] = 'foo';
var_dump($a);

string(11) "foobar

f"

PHP gotcha

$a = 11;
$a = $a++ + ++$a;
echo $a++;

PHP gotcha revealed
$a = 11;
$a = $a++ + ++$a;
echo $a++;

$a = 11;
$a = 11 + 13; //24
echo 24;

PHP gotcha
$array = array(1 => "Julien", "1" => "Seb", "Mag", 2 => "Leo");
echo count($array);

PHP gotcha revealed
$array = array(1 => "Julien", "1" => "Seb", "Mag", 2 => "Leo");
echo count($array);

$array = array( "1" => "Seb", 2 => "Leo");
2

PHP gotcha
$a = 'foo';
$b = 'bar';
echo $a . print('baz') . $b;

PHP gotcha revealed
$a = 'foo';
$b = 'bar';
echo $a . print('baz') . $b;

echo $a . print("baz" . $b);
"bazbarfoo1"

PHP gotcha

echo 0123 + 123 + 0;

PHP gotcha revealed

echo 0123 + 123 + 0;

echo 83 + 123 + 0;

PHP gotcha

$a = 'baz';
$a++;
echo $a;

PHP gotcha revealed

$a = 'baz';
$a++;
echo $a;

"bba"

PHP Tips
 PHP is full of functions and extensions
 Let's oversee some useful features

PHP Tip
 Array Flattening
$input = array('a', 'b', array('c', 'd'), 'e', array('f'), 'g');
$output = iterator_to_array(new RecursiveIteratorIterator(
new RecursiveArrayIterator($input)), FALSE);
var_dump($output);

array('a', 'b', 'c', 'd', 'e', 'f', 'g');

PHP Tip
 Automatic HTML cleaning
ob_start('ob_tidyhandler');
echo '<p>test</i>';

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 3.2//EN">
<html>
<head>
<title></title>
</head>
<body>
<p>test</p>
</body>
</html>

PHP Tip
 Get usefull info from MySQL
mysqli_report(MYSQLI_REPORT_INDEX);
$db = mysqli_connect('srv1', 'john', 'secret', 'my_db');
mysqli_query($db, "SELECT photo FROM Users WHERE source !='' LIMIT 1000");

PHP Warning: mysqli_query(): (00000/0): No index used in query/prepared
statement SELECT photo FROM Users WHERE source !='' LIMIT 1000

PHP Tip
 Apply a callback to every fetch from MySQL

$sql = "SELECT nom, prenom FROM auteurs";
$stmt = $pdo->query($sql);
$func = function ($nom, $prenom){printf('%s-%s',$nom,$prenom);};
$result = $stmt->fetchAll(PDO::FETCH_FUNC, $func);

PHP Tip
 List a type of weekday coming in calendar
$begin = new DateTime('2009-11-01');
$end = new DateTime; // now
$interval = DateInterval::createFromDateString('next sunday');
$period = new DatePeriod($begin, $interval, $end);
foreach ( $period as $dt ) {
echo $dt->format( "l Y-m-d H:i:sn" );
}

Sunday 2009-11-01 00:00:00
Sunday 2009-11-08 00:00:00
Sunday 2009-11-15 00:00:00
...

PHP Certification
 70 Questions – 90min
 PHP 5.5
 Functions – OOP – arrays – streams – Xml – Databases –
Json – strings – securité – Ios – HTTP ...
 Nothing known about how to pass the exam
 Better know maximum of subjects

PHP certif quick overview
What's the output of this script ?
<?php
function oranges(&$oranges = 17) {
$oranges .= 1;
}
$apples = 5;
oranges($apples);
echo $apples++;
A)16
B)51
C)15
D)6
E)52

What's design pattern can you recognize ?
<?php
class MyClassBuilder {
public function build() {
return new MyClass();
}
}
A)builder
B)factory
C)singleton
D)observer
E)other pattern

In SimpleXML, you can use ______ method on SimpleXmlElement
to get all its children

What's the output of this script ?
<?php
class Foo {
const BAR = 4+1;
}
echo Foo::BAR;
A)4
B)5
C)1
D)an error

PHP Tips for certification - OdW13

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