php-cert-aug-2021.md

PHP Certification - Aug 2021

Homework

• For Fri 03 Sep 2021
  • Quiz questions for course module 9 "Database"
  • Quiz questions for course module 10 "Security"
  • Quiz questions for course module 11 "Web Features"
  • Quiz questions for course module 12 "Error Handling"
  • Final Mock Exam
• For Wed 01 Sep 2021
  • Quiz questions for course module 7 "Functions"
  • Quiz questions for course module 8 "OOP"
  • Mock Exam #2
• For Mon 30 Aug 2021
  • Quiz questions for course module 4 "Strings and Patterns"
  • Quiz questions for course module 5 "Arrays"
  • Quiz questions for course module 6 "I/O"
  • Mock Exam #1
• For Fri 27 Aug 2021
  • Quiz questions for course module 2 "PHP Basics"
  • Quiz questions for course module 3 "Data Formats ..."

Docker Container Setup

• Download the ZIP file from the URL given by the instructor
• Unzip into a new folder /path/to/zip
• Follow the setup instructions in /path/to/zip/README.md

TODO

• Q: What is the class name used if unserialize() can't find the class def?

• Q: Find out where in the docs you would learn about zend.multibyte php.ini directive?

• A: It's listed under the Language Options section of the core php.ini settings documentation

• A: See: https://www.php.net/manual/en/ini.core.php#ini.sect.language-options

Class Notes

Overview of topics: https://www.zend.com/training/php-certification-exam Good overview of typical PHP program operation:

• https://www.zend.com/blog/exploring-new-php-jit-compiler

Bitwise Operators

Tutorial oriented towards the exam:

• https://www.w3resource.com/php/operators/bitwise-operators.php Truth table:

<?php
echo "Logical AND\n";
printf("%04b\n", 0b00 & 0b00);
printf("%04b\n", 0b00 & 0b01);
printf("%04b\n", 0b01 & 0b00);
printf("%04b\n", 0b01 & 0b01);

echo "Logical OR\n";
printf("%04b\n", 0b00 | 0b00);
printf("%04b\n", 0b00 | 0b01);
printf("%04b\n", 0b01 | 0b00);
printf("%04b\n", 0b01 | 0b01);

echo "Logical XOR\n";
printf("%04b\n", 0b00 ^ 0b00);
printf("%04b\n", 0b00 ^ 0b01);
printf("%04b\n", 0b01 ^ 0b00);
printf("%04b\n", 0b01 ^ 0b01);

Left/right shift illustration:

<?php
echo 16 << 3;
echo "\n";
echo 0b10000000;
echo "\n";

echo 16 >> 3;
echo "\n";
echo 0b00000010;
echo "\n";

echo 15 >> 3;
echo "\n";
echo 0b00000001;
echo "\n";

• Study up on gc_collect_cycles()

Data Formats

Read up on SimpleXMLElement

• https://www.php.net/manual/en/simplexml.examples-basic.php
• XPath Tutorial: https://www.w3schools.com/xml/xpath_intro.asp
• DateTime examples

<?php
$date[] = new DateTime('third thursday of next month');
$date[] = new DateTime('now', new DateTimeZone('CET'));
$date[] = new DateTime('@' . time());
$date[] = (new DateTime())->add(new DateInterval('P3D'));

var_dump($date);

• Study on DateTimeInterval and DateTimeZone and also "relative" time formats
• In addition, be aware of the basic time format codes

Strings

• Study the docs on sprintf() to get format codes for that family of functions
• Tutorial on PHP regex: https://www.w3schools.com/php/php_regex.asp
• Using regex to swap sub-patterns

<?php
$text = 'Doug Bierer';
$patt = '/(.*)\s(.*)/';
echo preg_replace($patt, '$2, $1', $text);

Functions

• Read up on Closure::bindTo()
  • https://www.php.net/manual/en/closure.bindto.php

OOP

• Read up on magic methods!
  • https://www.php.net/manual/en/language.oop5.magic.php
  • Don't worry about any methods added after PHP 7.1
  • __destruct() called when object goes out-of-scope
    • End of program
    • unset()
    • Called in a function and function call ends
    • Overwritten
• SPL
  • Make sure you study:
    • *Iterator* : just know what they are
    • ArrayIterator and ArrayObject make sure you're up to speed on these!
  • Just be aware of the "classic" data structure classes
• Generators
  • https://www.php.net/manual/en/class.generator.php
• Late Static Binding
  • https://www.php.net/manual/en/language.oop5.late-static-bindings.php
• Traits
  • https://www.php.net/manual/en/language.oop5.traits.php

Security Topic

Questions are drawn from here:

• https://www.php.net/manual/en/security.php Read up on the crypt() function
• https://www.php.net/manual/en/function.crypt.php

Change Request

• 2-57: answers s/be B & C; D answer makes assumption not born out by the question
• 6-19: s/be:

$options = [
    'http' => [
        'method'  => 'POST',
        'header'  => implode("\r\n", $headers),
        'content' => $query
    ]
];

• 8-16: "Class Member Overrides"
  • Example doesn't work because the child class fails to define the method in compliance with parent method requirements
• 8-97:
  • C ans is also correct, can use iterator_to_array() because ArrayObject is iterable