How does PHP internally represent strings?

Posted by Jim Thio on Programmers See other posts from Programmers or by Jim Thio
Published on 2012-06-02T14:41:03Z Indexed on 2012/06/02 22:49 UTC
Read the original article Hit count: 276

Filed under:

php

|

strings

UTF8?
UTF16?

Do strings in PHP also keep track of the encoding used?

Let's look at this script for example. Say I run:

$original = "??????????????";

What actually happens?

Obviously I think $original will not contain just 7 characters. Those glyphs must each be represented by several bytes there.

Then I do:

$converted = mb_convert_encoding ($original , "UTF-8");

What will happen to $converted? How will $converted be different from $original?

Will it be just the exact same byte sequence as $original but with a different encoding?

© Programmers or respective owner

Related posts about php

Magento, NGINX, PHP-FPM, APC, MEMCACHED, 16gb Ram CentOS, Spiking PHP-FPM to 100% CPU

as seen on Server Fault - Search for 'Server Fault'
I have been trying to resolve my issue of spiking cpu caused by php-fpm processes. I've reduced the php-fpm config settings to: pm = ondemand pm.max_children = 12 pm.start_servers = 2 pm.min_spare_servers = 2 pm.max_spare_servers = 10 pm.max_requests = 500 php_admin_value[memory_limit] = 128M Problem… >>> More
PHP Pear Installation on CentOS

as seen on Server Fault - Search for 'Server Fault'
[root@ip ~]# yum install php-pear* Reducing CentOS-5 Testing to included packages only Finished Setting up Install Process Package 1:php-pear-1.8.1-2.el5.centos.noarch already installed and latest versio … >>> More
Apache configurations for php "AddType text/html php" or "AddType application/x-httpd-php php .php"

as seen on Server Fault - Search for 'Server Fault'
I am taking over an application server and discover that it contain the following settings: AddType text/html php Although it works, but my understanding is that it should set as following: AddType application/x-httpd-php php .php What are the key differences between the two settings?… >>> More
mod_rewrite settings causes server to throw HTTP 500 errors instead of 404

as seen on Server Fault - Search for 'Server Fault'
Hello. I have a server with VBulletin forum (working under Apache 2.2, CentOS). The default settings for it in .htaccess are as follows: RewriteEngine on RewriteCond %{HTTP_HOST} ^gsmforum\.ru RewriteRule (.*) http://www.gsmforum.ru/$1 [R=301,L] # If you are having problems or are using VirtualDocumentRoot… >>> More
Problems installing Memcache (PECL extension)

as seen on Server Fault - Search for 'Server Fault'
I have installed memcached fine, and now I will need to install PECL extension memcache. Im running RedHat x86_64 es5. The installation gives me this: downloading memcache-2.2.6.tgz ... Starting to download memcache-2.2.6.tgz (35,957 bytes) ..........done: 35,957 bytes 11 source files, building running:… >>> More

Related posts about strings

References to other strings in strings.xml ?

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi Is it possible to reference other strings inside of strings.xml ? Something of the form: My string Here it is: android:id="@string/string_one" (If it did exist, there would of course be problems of circular, infinite definitions, etc. to beware of). Thanks. >>> More
Passing List of Strings or Array of strings into Unity Injection Constructor (Config-Based)

as seen on Stack Overflow - Search for 'Stack Overflow'
I cannot seem to get unity working when attempting to pass in an array of strings into a constructor parameter list, while using XML configuration. When I try the following: <typeConfig ...> <constructor ...> <param ... parameterType="System.String[]"> <array>… >>> More
Strings in array are no longer strings after jQuery.each()

as seen on Stack Overflow - Search for 'Stack Overflow'
I'm pretty confused with the behaviour of arrays of strings when I loop them through the jQuery.each() method. Apparently, the strings become jQuery objects inside the callback function. However, I cannot use the this.get() method to obtain the original string; doing so triggers a this.get is not… >>> More
Complete if statement with strings and array of strings

as seen on Stack Overflow - Search for 'Stack Overflow'
I have a page that has 3 variables. They look like this: String[] Headers = new String[] { "Max Width", "Max Length", "Max Height" }; String currentHeader = (String)HttpContext.Current.Request.QueryString["ItemHas"] ?? ""; String checkString = (String)HttpContext.Current.Request.QueryString["ItemIn"]… >>> More
[C++] Index strings by other strings

as seen on Stack Overflow - Search for 'Stack Overflow'
Hello, I need to index specific strings with other strings and I can't really find a good way to do so. I tried to use tr1::unordered_map, but I'm having some difficulties using it. If someone could tell me what is the best way to do that I'd be really grateful :) I also need to index objects by a… >>> More