It has a wealth of uses within PHP as it allows you to cut up a string easily. The string that this function returns is referred to as the substring. In addition, the function gives you control over both the offset and the length of the string. The width example uses string length instead since I know it will always be at the end of the string. PHP’s substr () function allows you to take a string and only return a portion of it. This is why there is subtraction done when calculating the height. Substr requires the string it will be processing, the starting point, and the LENGTH of the string to capture. It then figures out the starting and ending position of where the delimiter is found. You don't need to use multiple characters like I did, but make sure you have enough characters so it doesn't capture something else in the string. Then figure out where each delimiter starts and ends. You can also set them programmatically if you wish. $width = substr($imageURL, $strPosStart, $strPosEnd) īasically, define your string delimiters. $height = substr($imageURL, $strPosStart, $strPosEnd) $strPosEnd = strpos($imageURL, $secondDelimiter)-$strPosStart $strPosStart = strpos($imageURL, $firstDelimiter)+3 Ademas, trabaja en las siguientes versiones de (PHP 4, PHP 5, PHP 7, PHP 8). La definicin de esta funcin para operar con cadenas es la siguiente: Funcin substr() Esta funcion opera en base a una cadena dada y nos devuelve parte de una cadena. Here is working code that I used to find the height and width of an image using delimiters, strpos, strlen, and substr. Vamos a ver cmo extraer palabras de una cadena con PHP substr(). Some of the answers related to strpos, strlen, and using delimiters are wrong. This is a good practice generally when using the global scope for your helper functions.There's a lot of good answers here. This keeps it from breaking in case you upgrade and forget that you added it. If you do not have PHP 8, you can use these functions to get the capability of the new string functions.īut! Remember to use a conditional check to make sure the function is not already defined. With credit to Paul Phillips for the original polyfill posted. In this case, the replace, offset and length parameters may be provided either as scalar values to be applied to each input string in turn, or as array s, in which case the corresponding array element will be used for each input string. Getting Started Introduction A simple tutorial Language Reference Basic syntax Types Variables Constants Expressions Operators Control Structures Functions Classes and Objects Namespaces Enumerations Errors Exceptions Fibers Generators Attributes References Explained Predefined Variables Predefined Exceptions Predefined Interfaces and Classes Predefined Attributes Context options and parameters Supported Protocols and Wrappers Security Introduction General considerations Installed as CGI binary Installed as an Apache module Session Security Filesystem Security Database Security Error Reporting User Submitted Data Hiding PHP Keeping Current Features HTTP authentication with PHP Cookies Sessions Dealing with XForms Handling file uploads Using remote files Connection handling Persistent Database Connections Command line usage Garbage Collection DTrace Dynamic Tracing Function Reference Affecting PHP's Behaviour Audio Formats Manipulation Authentication Services Command Line Specific Extensions Compression and Archive Extensions Cryptography Extensions Database Extensions Date and Time Related Extensions File System Related Extensions Human Language and Character Encoding Support Image Processing and Generation Mail Related Extensions Mathematical Extensions Non-Text MIME Output Process Control Extensions Other Basic Extensions Other Services Search Engine Extensions Server Specific Extensions Session Extensions Text Processing Variable and Type Related Extensions Web Services Windows Only Extensions XML Manipulation GUI Extensions Keyboard Shortcuts ? This help j Next menu item k Previous menu item g p Previous man page g n Next man page G Scroll to bottom g g Scroll to top g h Goto homepage g s Goto search An array of string s can be provided, in which case the replacements will occur on each string in turn.
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