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Created by magnum on September 11, 2011 19:46:09    Last update: September 11, 2011 19:46:09
A pair of C functions convert between an Internet address and a string (ASCII): #include <arpa/inet.h> /* * Returns a poin... However , these functions do not support IPv6. The new pair is: #include <arpa/inet.h> /* Convert a Internet ad... Examples: #include <sys/socket.h> #include <netinet/in.h>...
Created by jinx on April 25, 2011 12:43:40    Last update: April 25, 2011 12:43:40
Use the PHP function method_exists to check if the class or object has a certain method. It returns TRUE if the method exists (even when the value of the property is NULL), FALSE if the method does not exist. Example: <?php class A { var $p = 'A property'; ... Outputs: Class A has method f1: bool(true) Object $a has... Also note that C++-like method overloading does not exist in PHP. Thus there's no ambiguity about which version of the method exists, i.e., with no argument, with one argument... etc. The following code generates Fatal error: <?php class A { var $p = 'A property'; ...
Created by jinx on April 25, 2011 11:50:09    Last update: April 25, 2011 11:51:53
Use the PHP function property_exists to check if the class or object has a certain property. It returns TRUE if the property exists (even when the value of the property is NULL), FALSE if the property does not exist, or NULL in case of an error. Example: <?php class A { var $p = 'A property'; ... Outputs: Class A has property $p: bool(false) Class A ha...
Created by Dr. Xi on April 18, 2011 12:10:37    Last update: April 18, 2011 12:14:24
Python defines a long list of special methods to customize class behavior. This is a short list for the Basic Customizations . Method Description object.__new__(cls[, ...]) Called to create a new instance of class cls. __new__() is a static method (special-cased so you need not declare it as such) that takes the class of which an instance was requested as its first argument. __new__() is intended mainly to allow subclasses of immutable types (like int, str, or tuple) to customize instance creation. It is also commonly overridden in custom metaclasses in order to customize class creation. object.__init__(self[,...]) Called when the instance is created. The arguments are those passed to the class constructor expression. If a base class has an __init__() method, the derived class’s __init__()...
Created by Dr. Xi on November 18, 2010 22:13:36    Last update: November 18, 2010 22:13:36
You can use the eval function to substitute a value defined by a variable. Suppose you have a string literal $a = 'a $string' and you want Perl to substitute $string with the value of the $string variable. This is normally not a problem. Because if you use double quote, Perl does the interpretation automatically: $string = 'theactual'; $a = "a $string"; pri... But this doesn't work if the value of $string isn't available when you define the template $a . In this case, you have to use single quote to preserve the template definition. But you can use eval to do the replacement when the value of $string becomes available: #!/usr/bin/perl $a = 'a $string'; $string = ...
Created by James on June 30, 2010 20:14:28    Last update: July 03, 2010 18:41:12
The HTML page <!DOCTYPE html> <html> <head> <title>jQu... Client Side Code // called before upload submit function sta... Server Side Code Using Apache Commons FileUpload as example. Upload code (responds to fileUpload.do ): final HttpSession session = httpServletRequest... Progress code (responds to uploadProgress.do ): HttpSession session = httpServletRequest.getSe...
Created by Dr. Xi on February 17, 2008 19:38:29    Last update: February 17, 2008 19:43:41
To get the autonumber value of the last insertion (use MySQL as example): #!/usr/bin/perl use DBI; use DBIConst; ...