It’s hard to describe this scenario precisely with limited title length. Basically, this is when you want to dedicate a field in ‘category‘ table to store the number of articles or posts in ‘post‘ table that fall into this category. Previously, you had both ‘category’ table to store post categories and ‘post’ table to store …
MySQL: Add Statistics Column for the Number Count of Records from Another Table Read More »
Different number notations for different numerical bases: 0144 // base 8 100 // base 10 0x64 // base 16 To convert between number bases, use PHP base_convert() function: $hex = ‘a1’; // hexadecimal number (base 16) $decimal = base_convert($hex, 16, 10); // $hex converted from base 16 to base 10 and $decimal is now 161 …
Degrees and radians are different metric means to gauge an angle. They are mutually convertible in PHP. Simply use the PHP degrees to radians function deg2rad() and PHP radians to degrees function rad2deg(). $degrees = 180; $radians = deg2rad($degrees); // 3.1416 $degrees = rad2deg($radians); // 180 Because trigonometric calculations are usually done in radians, you …
PHP: Convert Degrees to Radians and Convert Radians to Degrees Read More »
To display numbers to end users, especially large numbers, you may need to format them to be more user friendly. For example, with a large integer 43386000.75, it is usually preferred to comma-separate every 3 digits to this: 43,386,000.75 To format numbers this way in PHP, you need number_format() function: print number_format(43386000.75); // prints ‘43,386,000.75’ …
PHP: Number Format Function to Format Numbers in PHP (Integer or Float) Read More »
As we all know the simplest approach to create an email message and send it out is to use the php mail() function. A typical usage example would be: mail(‘[email protected]’, ‘Subject Title’, ‘Message body goes here.’); However, as the mail() function sends emails in text/plain mime type by default, if you include HTML code in …
Some strings of texts may lack necessary wraps and don’t have natural line breaks in them so that the lines are too long to read comfortably. Therefore, you want a way to insert line breaks in to the string every dozens of characters. The php function you need is wordwrap(): $s = ‘ … ‘; …
PHP: Wrap Long Lines | Insert Line Breaks into a Long String Read More »
It’s common that you need to reformat the texts in PHP and make them look a little more formal. For example, the first letter of all sentences should be uppercased, or with a title, the first letter of all words should also be made uppercase; in other situations, you may want all letters to be …
Everyone who ever dealt with formatting code in PHP string manipulations may want to switch between different tab sizes or simply change spaces to tabs or tabs to spaces in the formatted code string. The function we’ll need for these is str_replace(), the string search and replace php function. For example: Switch between tabs and …
If you want to loop through a literal string in PHP and have the opportunity to look and process each of the characters one character at a time, use the following snippet: $string = "Hooray"; for ($i = 0, $j = strlen($string); $i < $j; $i++) { echo $string[$i].’, ‘; } There you go, just …
PHP: How to process a string one byte (character) at a time Read More »
As a web site templating language, string processing is what PHP is good at. There’s always a chance that you need to verify and make sure if a string contains another string. For example, to check if an at sign is included in the entered email address by a visitor: if (strpos($_POST[’email’], ‘@’) !== false) …
PHP: Check if a string contains another string or substring Read More »
Programmably, there are several different types of date and time in PHP you can create and process. Consequently, you have several types of current date and time in PHP that can be generated and used. Below is a list of functions that returns the current date and time: The current Unix timestamp: time() The current …
Ideally, global variables outside a function can not and should not be accessed from within the function to hold up the programming modularization paradigm. However, if you really need to do this, especially in small programs, you can declare the variable again inside the function by the keyword ‘global‘ so as to use inside the …
PHP: How to access a global variable inside a function without passing it? Read More »
As we all know that JavaScript is usually what involves in detecting different browsers and their varying capabilities. PHP has the very function that parses the HTTP request headers sent by client web browsers so as to determine the identify of the requesting browser as well as its capabilities. To get client browser information and …
One of the things the remote web server inspects is the client cookie to know about the requester. If you need cURL to simulate a user browser that sends cookie information to the web server, you need the following options: $c = curl_init(‘http://www.example.com/needs-cookies.php’); curl_setopt ($c, CURLOPT_COOKIE, ‘user=ellen; activity=swimming’); curl_setopt ($c, CURLOPT_RETURNTRANSFER, true); $page = curl_exec …
PHP cURL: Fetching URL and Sending Request with Cookies Read More »
By default, all HTTP requests made out by cURL is GET requests that simply fetches the URL and don’t submit any more POST variables. However, if you need to fetch and retrieve URL by the POST method with cURL, you need the snippet below: $url = ‘http://www.example.com/submit.php’; // The submitted form data, encoded as query-string-style …
To draw a line, use ImageLine( ): ImageLine($image, $x1, $y1, $x2, $y2, $color); To draw an open rectangle, use ImageRectangle( ): ImageRectangle($image, $x1, $y1, $x2, $y2, $color); To draw a solid rectangle, use ImageFilledRectangle( ): ImageFilledRectangle($image, $x1, $y1, $x2, $y2, $color); To draw an open polygon, use ImagePolygon( ): $points = array($x1, $y1, $x2, $y2, …
Debugging a PHP script, you may want to alter the error-displaying sensitivity on a particular page and control what types of errors should be reported. The solution is the PHP error reporting function error_reporting(): error_reporting(E_ALL); // everything error_reporting(E_ERROR | E_PARSE); // only major problems error_reporting(E_ALL & ~E_NOTICE); // everything but notices As the parameters of …
PHP: Change Error Reporting Level | Different PHP Error Types Read More »
A hash or digest can be thought of as the digital fingerprint of a piece of data. Hash is usually generated from any string of text in a fixed length by a one-way mathematical process. It is next to impossible to re-engineer the original text or data from the hash alone. Also, it is vast …
PHP: What is Hash? | Hashing a String | Generate Hash of Strings Read More »
Back tick ` in PHP is used to read the output from another program, usually external commands in Linux shell, much like the way a pipe does the job with bash. In PHP, Backtick “ embraced string is treated a command and executed externally in shell, returning the execution results from the standard output. For …
Of course, you will have to read in the file first, preferably in an array. To read a file in an array, you just need the file() function: $lines = file(‘quotes.txt’); Then, you shuffle the array with shuffle() function that randomizes all the items in the array thus shuffling the lines in the file quotes.txt: …
PHP: Randomizing All Lines of a File – Shuffle Lines in a Text File Read More »
