Tutorial by Examples: n

Redis provides the LPOP and RPOP commands as a counterpart to the LPUSH and RPUSH commands for fetching data items. If I was working with a list my_list that had several data items in it already, I can get the first item in the list using the LPOP command: LPOP my_list The result of this comman...

Openfire it's available to download at Ignite Realtime website It's also possible to download relative source codeenter link description here Windows installer: Just execute the exe and follow basic instructions as any program (installation directory, shortcut etc.). Unix-Linux-Mac install:...

The basic Redis command for adding an item to a set is SADD. It takes a key and one or more members and adds them to the set stored at the given key. For example, lets say that I wanted to create a set with the items apple, pear and banana. I could execute either of the following: SADD fruit app...

Redis supplies the SISMEMBER command to test if a particular item is already a member of a set. Using the SISMEMBER command I can test and see if apple is already a member of my fruit set. If I construct my fruit set from the previous example, I can check and see if it contains apple using the fol...

Redis provides the ZADD command to add items to a sorted set. The basic form of the ZADD command is to specify the set, the item to add and it's score. For example, if I wanted to construct an ordered set of my favorite food (from least to most), I could use either of: zadd favs 1 apple zadd fav...

Redis provides seven different operations for working with scripts: Eval operations (EVAL, EVALSHA) SCRIPT operations (DEBUG, EXISTS, FLUSH, KILL, LOAD) The EVAL command evaluates a script provided as a string argument to the server. Scripts can access the specified Redis keys named as argum...

Be aware that the WebBrowser control is not sympathetic to your XAML definition, and renders itself over the top of other things. For example, if you put it inside a BusyIndicator that has been marked as being busy, it will still render itself over the top of that control. The solution is to bind th...

Insertion sort is one of the more basic algorithms in computer science. The insertion sort ranks elements by iterating through a collection and positions elements based on their value. The set is divided into sorted and unsorted halves and repeats until all elements are sorted. Insertion sort has c...

Bubble Sort This is a simple sorting algorithm that repeatedly steps through the list to be sorted, compares each pair of adjacent items and swaps them if they are in the wrong order. The pass through the list is repeated until no swaps are needed. Although the algorithm is simple, it is too slow ...

Selection sort is noted for its simplicity. It starts with the first element in the array, saving it's value as a minimum value (or maximum, depending on sorting order). It then itterates through the array, and replaces the min value with any other value lesser then min it finds on the way. That min...

Since we have many different algorithms to choose from, when we want to sort an array, we need to know which one will do it's job. So we need some method of measuring algoritm's speed and reliability. That's where Asymptotic analysis kicks in. Asymptotic analysis is the process of describing the ef...

Quicksort is one of the advanced algorithms. It features a time complexity of O(n log n) and applies a divide & conquer strategy. This combination results in advanced algorithmic performance. Quicksort first divides a large array into two smaller sub-arrays: the low elements and the high element...

g + geom_bar(aes(x = cut, fill = color), position = "fill") + guides(fill = guide_legend(title = NULL))

g + geom_bar(mapping = aes(x = cut, fill = clarity), position = "dodge") + theme(axis.text = element_text(colour = "red", size = 12))

g + geom_histogram(aes(price, fill = cut), binwidth = 500) + labs(x = "Price", y = "Number of diamonds", title = "Distribution of prices \n across Cuts") + theme(plot.title = element_text(colour = "red", face = "italic"), ...

If you need to select between several options, enabling just one via enable_if<> can be quite cumbersome, since several conditions needs to be negated too. The ordering between overloads can instead be selected using inheritance, i.e. tag dispatch. Instead of testing for the thing that ne...

Installation: To install the LoopBack command-line interface (CLI) tool: npm install -g loopback-cli This installs the lb command-line tool for scaffolding and modifying LoopBack applications. Create new application: To create a new application: lb The LoopBack application generator will ...

This is the typical approach for novice developers building SQL action queries. They are vulnerable to the Bobby Tables type SQL Injection attacks. Dim strSQL As String strSQL = "INSERT INTO Employees chrFirstName, chrLastName, chrPhone " _ & "VALUES ('" & M...

Detailed instructions on getting opengl-es-2.0 set up or installed.