PHP Collective

If user input is inserted without modification into an SQL query, then the application becomes vulnerable to SQL injection, like in the following example: $unsafe_variable = $_POST['user_input']; ...

Consider: $a = 'How are you?'; if ($a contains 'are') echo 'true'; Suppose I have the code above, what is the correct way to write the statement if ($a contains 'are')?

What is this? This is a collection of questions that come up now and then about syntax in PHP. This is also a Community Wiki, so everyone is invited to participate in maintaining this list. This ...

If I have a YouTube video URL, is there any way to use PHP and cURL to get the associated thumbnail from the YouTube API?

Is there an easy way to delete an element from an array using PHP, such that foreach ($array) no longer includes that element? I thought that setting it to null would do it, but apparently it does ...

How can one parse HTML/XML and extract information from it?

How can I write two functions that would take a string and return if it starts with the specified character/string or ends with it? For example: $str = '|apples}'; echo startsWith($str, '|'); //...

I'm trying to create a randomized string in PHP, and I get absolutely no output with this: <?php function RandomString() { $characters = '...

I have checked my PHP ini file (php.ini) and display_errors is set and also error reporting is E_ALL. I have restarted my Apache webserver. I have even put these lines at the top of my script, and it ...

In PHP 5, what is the difference between using self and $this? When is each appropriate?

How can I get the client IP address using PHP? I want to keep record of the user who logged into my website through his/her IP address.

Is it possible to redirect a user to a different page through the use of PHP? Say the user goes to www.example.com/page.php and I want to redirect them to www.example.com/index.php, how would I do so ...

I have an array: array( 4 => 'apple', 7 => 'orange', 13 => 'plum' ) I would like to get the first element of this array. Expected result: string apple One requirement: it cannot be ...

I know that PHP doesn't yet have native Enumerations. But I have become accustomed to them from the Java world. I would love to use enums as a way to give predefined values which IDEs' auto-completion ...

Which PHP function can return the current date/time?

What are the technical reasons for why one shouldn't use mysql_* functions? (e.g. mysql_query(), mysql_connect() or mysql_real_escape_string())? Why should I use something else even if they work on ...

I have an HTML (not XHTML) document that renders fine in Firefox 3 and IE 7. It uses fairly basic CSS to style it and renders fine in HTML. I'm now after a way of converting it to PDF. I have tried:...

What is this? This is a number of answers about warnings, errors, and notices you might encounter while programming PHP and have no clue how to fix them. This is also a Community Wiki, so everyone is ...

In PHP: When should I use require vs. include? When should I use require_once vs. include_once?

PHP treats all arrays as associative, so there aren't any built in functions. Can anyone recommend a fairly efficient way to check if an array "is a list" (contains only numeric keys ...

Given the following code: DB::table('users')->get(); I want to get the raw SQL query string that the database query builder above will generate. In this example, it would be SELECT * FROM users. ...

I'm running a PHP script and continue to receive errors like: Notice: Undefined variable: my_variable_name in C:\wamp\www\mypath\index.php on line 10 Notice: Undefined index: my_index C:\wamp\www\...

I'm integrating an API to my website which works with data stored in objects while my code is written using arrays. I'd like a quick-and-dirty function to convert an object to an array.

I installed node using homebrew (Mojave), afterwards php stoped working and if I try to run php -v I get this error: php -v dyld: Library not loaded: /usr/local/opt/icu4c/lib/libicui18n.62.dylib ...

I use this code to get the full URL: $actual_link = 'http://'.$_SERVER['HTTP_HOST'].$_SERVER['PHP_SELF']; The problem is that I use some masks in my .htaccess, so what we see in the URL is not always ...

Some elements in my array are empty strings from users. $linksArray still has empty elements after the following: foreach($linksArray as $link) { if($link == '') { unset($link); } }...

I have a PHP array like so: $messages = [312, 401, 1599, 3, ...]; Given that the values in the array are unique, how can I delete the element with a given value (without knowing its key)?

This is a question you can read everywhere on the web with various answers: $ext = end(explode('.', $filename)); $ext = substr(strrchr($filename, '.'), 1); $ext = substr($filename, strrpos($filename, '...

How to find number of days between two dates using PHP?

I have a bunch of client point of sale (POS) systems that periodically send new sales data to one centralized database, which stores the data into one big database for report generation. The client ...

How can I sort this array by the value of the "order" key? Even though the values are currently sequential, they will not always be. Array ( [0] => Array ( [...

I am trying to select data from a MySQL table, but I get one of the following error messages: mysql_fetch_array() expects parameter 1 to be resource, boolean given This is my code: $username = $...

I have two dates of the form: Start Date: 2007-03-24 End Date: 2009-06-26 Now I need to find the difference between these two in the following form: 2 years, 3 months and 2 days How can I do this ...

I want to convert these types of values, '3', '2.34', '0.234343', etc. to a number. In JavaScript we can use Number(), but is there any similar method available in PHP? Input Output '2' ...

I want to return JSON from a PHP script. Do I just echo the result? Do I have to set the Content-Type header?

Quite often I will try and run a PHP script and just get a blank screen back. No error message; just an empty screen. The cause might have been a simple syntax error (wrong bracket, missing semicolon),...

When running my script, I am getting several errors like this: Warning: Cannot modify header information - headers already sent by (output started at /some/file.php:12) in /some/file.php on line 23 ...

When and why should I use public, private, and protected functions and variables inside a class? What is the difference between them? Examples: // Public public $variable; public function ...

I want to put a copyright notice in the footer of a web site, but I think it's incredibly tacky for the year to be outdated. How would I make the year update automatically with PHP?

Please define what stdClass is.

I'm building a PHP script that feeds JSON data to another script. My script builds data into a large associative array, and then outputs the data using json_encode. Here is an example script: $data = ...

I need to keep a session alive for 30 minutes and then destroy it.

What's the correct way to round a PHP string to two decimal places? $number = "520"; // It's a string from a database $formatted_number = round_to_2dp($number); echo $formatted_number; The output ...

Is there a catchall function somewhere that works well for sanitizing user input for SQL injection and XSS attacks, while still allowing certain types of HTML tags?

What's the best way to determine the first key in a possibly associative array? My first thought it to just foreach the array and then immediately breaking it, like this: foreach ($an_array as $key =&...

Today I needed to install the IBM DB2 library. I went through all the steps up to make install, and I found ibm_db2.so in $PHP_HOME/lib/extensions/somecomplicatedname/ibm_db2.so. The great catch is ...

I'm setting up a new server and want to support UTF-8 fully in my web application. I have tried this in the past on existing servers and always seem to end up having to fall back to ISO-8859-1. Where ...

I have searched on the web for over two days now, and probably have looked through most of the online documented scenarios and workarounds, but nothing worked for me so far. I am on AWS SDK for PHP V2....

Let me prefix this by saying that I know what foreach is, does and how to use it. This question concerns how it works under the bonnet, and I don't want any answers along the lines of "this is how you ...

Ok, I know all about array_pop(), but that deletes the last element. How to get the last element of an array without deleting it? Here's a bonus: $array = array('a' => 'a', 'b' => 'b', 'c' =>...