Making a JS array unique isn’t a simple one-liner. This short article is for developers trying to make a JavaScript array unique without leaving holes in your array. Sorting an array in JavaScript is simple in most cases. Just call the sort() method on the array like so.

var my_array = [5, 2, 4, 6, 9];
my_array.sort();

One caveat to be aware of with this method of sorting is that it performs a non-lexicographical sort, which might be confusing for human users if you display it on screen. Depending on your requirements, you might want to change your sorting algorithm. Check out Brian Huisman’s article on the subject.

After sorting the array, the following snippet will remove any duplicate entries

for ( var i = 1; i < my_array.length; i++ ) {
    if ( my_array[i] === my_array[ i - 1 ] ) {
        my_array.splice( i--, 1 );
    }
}

This will iterate over each element in the array, attempting to find elements where the value is equal to the previous value. If they are equal, we have found a duplicate so we remove it using splice.

A complete function for sorting and making an array unique in JavaScript would look like the following

function sort_and_unique( my_array ) {
	my_array.sort();
	for ( var i = 1; i < my_array.length; i++ ) {
		if ( my_array[i] === my_array[ i - 1 ] ) {
					my_array.splice( i--, 1 );
		}
	}
	return my_array;
};

Image Loading Instructions

• Include jQuery
• Include jquery.krioImageLoader.js
• Instantiate the plugin on the wrapper
• $(“#test”).krioImageLoader();
• Watch it load

View the Demo
Download or fork on GitHub

The PayPal script will accept the users credentials on your website and send a request to PayPal to verify and bill the users information. From the script you can enter the amount to be billed, the timeframe, and any setup fees for the services.

Downloads, specific instructions and requirements for the script can be found on its GitHub page here.

For testing purposes you should setup a PayPal sandbox account. This will allow you to test your scripts. PayPal will verify the cards, however it will not attempt to charge them. PayPal will also provide dummy feedback into your PayPal user account page.

Download the script on GitHub.

The Crypt library provides classes and methods that help software/web developers to easily and securely encrypt data. The steps involved in encrypting data are detailed below.

1. Choose which library you want to use. The Rijndael is currently considered to be the most secure.
2. Create a new key that is used to decrypt the data later.
3. Encrypt the string/data.
4. Transfer the encrypting data.
5. Decrypt using the original key.

First, make sure to require the appropriate Ruby libraries net/http and uri. Next we will utilize the post_form method from HTTP, using the websites URL and a hash comprised of the POST key/value that you want to send in. You can use multiple values in the hash if necessary.

Running the parse method from URI will automatically format the URL you pass to the post_form method for easy manipulation.

The value returned and placed into the postData variable is a string representation of the source returned after your post request. This is a simple solution to a question that web developers often have.

Typically when making an HttpWebRequest with C# you would write something to this effect:

HttpWebRequest request = (HttpWebRequest)WebRequest.Create("http://URL.org");
HttpWebResponse response = (HttpWebResponse)request.GetResponse();

This will work fine, however your connection will not be anonymous. Using Tor, you can effectively create an anonymous connection. First, make sure to install Tor and run it. The typical Tor Windows install will install Privoxy along with Vidalia. To make your C# web request run through Tor, you need to override the default proxy property to contact Prioxy.

HttpWebRequest request = (HttpWebRequest)WebRequest.Create("http://URL.org");
request.Proxy = new WebProxy("127.0.0.1:8118"); // default privoxy port for tor
HttpWebResponse response = (HttpWebResponse)request.GetResponse();

127.0.0.1:8118 is the default address for Privoxy. Your HttpWebRequest will now be routed through Tor. Make sure that you do not have any firewalls blocking this default port.

Why use .NET?

.NET allows us to leverage existing code from other .NET languages and integrate them together into one language unspecific assembly. This allows programming to use many existing code samples into their applications, which can help to improve development time and decrease costs. .NET provides a single runtime engine that all .NET supported languages can use together with typical debugging and inheritance features. .NET’s extensive base class library can be leveraged to deploy more feature-rich applications in a shorter time frame.

What makes .NET tick?

.NET is primarily comprised of a runtime environment combined with a base class library.  There are three main features that make .NET into the powerful solution that is it.

• CLR – Common Language Runtime
• CTS – Common Type System
• CLS – Common Language Specification

While you do now need to know what is happening under the hood of these three entities you do need to have an understanding of their purposes.

.NET’s Common Language Runtime

This is .NET’s runtime environment that is used to control aspects of .NET, such as data types. The CLR will keep memory in a stable state, it will provide application management, and thread allocation (multi CPU platforms). Another important feature of the CLR is its duty to manage security on the host machine related to your application.

.NET’s Common Type System

The CTS is utilized to define standard compliant type definitions for .NET applications. If you want your C# application to play nicely with other programming languages, you will want to make sure to use data types that the CTS states are compliant. The CTS also defines how these standard types will integrate with each other. C# allows you to utilize types that are not defined in the CTS and while you are more than welcome to take advantage of them in your scripts, be warned that you will not be able to pass these data types to a language that does not support it. You can however, utilize the type inside of a function, but not return it to another language, which the system does support.

.NET’s Common Language Specification

When envisioning the CLS, picture it as a subset of the Common Type System. It is the part of the CTS that actually makes the definitions of what is compatible and what types can be used together in unison. Through the compiler, you can test for CTS compatibility.

.NET Libraries

One of the most important features that .NET brings to programming is its base class library that supports all .NET languages. The .NET base class library provides useful classes related to database interaction, security, input & output file operations, XML integration, and even visual desktop integration. Think of the .NET base class library as a collection of code that you can leverage to develop applications more quickly and efficiently.

C#’s role in .NET

C# is Microsoft’s programming language developed specifically to provide seamless integration with .NET. While .NET does support other programming languages that have been around from before C#, Microsoft felt that they needed a new language that would be able to rival more advanced languages that their existing languages simply could not. Thus C# was born with the advanced language features that programmers needed. C# inherits from many C-style languages and even functional languages, such as LISP.

C# Compilation

When you put your C# source code through the C# compiler it is converted into an intermediate language known as the Common Intermediate Language, or CIL. This intermediate language is in the form of an .exe or dll file. Similarly, if you are using Visual Basic, your source code would be compiled into the intermediate language that would look very similar to your C# code. This is how .NET is able to allow different programming languages to work together. The intermediate language and meta data that accompanies it is setup in such a way by the compiler that it is portable between languages. When your program is run and the CLR (.NET runtime) references a piece of code in the CIL that is then compiled into instructions that can be run on your specific machine. This compiled code will look different depending on your operating system and speed of your computer. For example, mobile applications will most likely have less memory available and the runtime will take this into account before final compilation of the CIL (intermediate language) into machine specific instructions.

The method that is used to take the CIL (intermediate language) and produce the final instructions is known as the just-in-time compiler. The just-in-time compiler (JIT) produces code specific to the target machine. One important feature of the JIT is its ability to cache its output for the future if it is likely that a piece of code will be run again in the future, thus it will not need to compile it again.

The .NET System namespace in the base class library

Namespaces are used in .NET to group related libraries and types. Under the System library we have many assemblies, such as System.Collections, which deals with container types, and System.Drawing, which provides user interface tools for creating desktop apps. You cannot expect to build any useful applications in C# without referencing at least the System namespace in your applications. Namespaces can contain any number of nested namespaces. Thus we see System.Xml and System.Security, which are both nested inside of the System namespace.

This seems to be a good time to showcase our first piece of C# code. Below you can see how one would typically include these namespace into code.

using System;
using System.Collections;
public class OurArrayList {

   public static void Main()  {

      // create ourList array
      ArrayList ourList = new ArrayList();
      ourList.Add("Krio");
      ourList.Add("is");
      ourList.Add("awesome");
   }
}

This example shows how you would reference a namespace at the top of your C# code. Once you utilize the ‘using’ keyword and reference a namespace you can call the classes located inside of that namespace. In this example we are instantiating the ArrayList class into the object ourList and utilizing the method Add.

Section 1 Conclusion

This first section in the Learning C# 2010 along with .NET 4 series has provided you with a firm foundation related to gaining an understanding of what happens in the background when you create C# applications with .NET. In addition, you have a functional understanding of the base class library and how to integrate a namespace.

First, you’ll need a MySQL result set. To do that you’ll need to select something from your database and loop through it like so:

$result = mysql_query("SELECT * FROM my_table");

while($row = mysql_fetch_assoc($result)) {

// inside the loop

}

The problem is, if you want to loop through the same result set again, you will get an error because the internal pointer is currently at the end of the result. You will need to put the pointer back at the beginning of the result set so that you can loop through it again.

You can do it with a helpful php function named mysql_data_seek.

mysql_data_seek($result, 0); // set the pointer of the result set back to the beginning.

while($row2 = mysql_fetch_assoc($result)) {

// inside the loop

}

This demonstrates how, as a PHP website developer, you can reset the pointer of a MySQL result set, which will allow you to iterate through the result set for a second time.

Who is this C# tutorial series for?

There will be two ideal targets for this tutorial series on C#. Individuals who has never programed before and professional programmers looking to learn to program in C#. The sections will be clearly outlined so that individuals will know which section is right for them. This means that individuals with experience in coding (any language will do) who have dealt with object oriented techniques in the past will most likely not need to spend much time learning about variables, while new programmers will need to spend more time on these sections. This series will concentrate on providing programmers with instruction, examples, and tutorials that will provide a strong base for coding syntactically clean, scalable, and standards compliant C# applications for the windows platform.

Learning C# 2010 Series Outcomes

For New Programmers

• Learn about programming language keywords, such as syntax, comments, datatypes, variables, loops, and functions.
• Gain the ability to code complex, scalable, and standards compliant C# applications in a professional environment.
• Quickly move on to learning more advanced features that will get you developing useful applications in no-time.
• New Programmers will need to read the articles title ‘Essentials’, which are targeted towards individuals with no previous coding experience.

For Experienced Programmers

• Quickly learn how the basics are created in C#, such as variables, loops, libraries, and objects.
• Move on to more specific areas, such as generics, multi-threaded applications, and so on.
• Learn Microsoft’s flagship platform and programming language.
• Transfer your existing programming knowledge to the C# language.
• Gain the ability to code complex, scalable, and standards compliant C# applications in a professional environment.
• Coders with experience in other programming languages may find it beneficial to skip the articles labeled ‘Essentials’. If you feel lost during a technical discussion, just come back to these articles as they will lay the programming foundations.

Learning C# 2010 along with .NET 4 Sections

.NET Overview

Learning C# – .NET Overview
This section will give you the necessary knowledge related to how .NET programming languages work and how the code you write in future chapters is executed. It will cover what happens when you compile your application along with how the various .NET programming languages, such as C#, VB, and F# can work together if you keep your code standards compliant. Base class libraries will be explored along with the .NET runtime environment.

Note: I will be releasing articles and tutorials as I am able to write them. Not necessarily at one time. I will also be released video tutorials that will use these articles are learning outcome references.

The ternary operator is a shorthand if/else statement. It allows developers to form conditions quickly and in a very readable fashion.

Here is the ternary syntax

(condition) ? true-stuff-here : false-stuff-here;

Here is an example of the ternary operator

$age = 20;

$response = ($age > 29) ? "He's in his thirties" : "He's not";

echo $response; // He's not

I hope you can see the usefulness in the ability for the ternary operator to easily perform conditional comparisons. Please however, refrain from using ‘nested ternary comparisons’ as the are very difficult to so read. It is so frowned upon by web developers that I’m not even going to post an example.