Tutorial by Examples: s

import React from 'react'; class SearchEs6 extends React.Component{ constructor(props) { super(props); this.state = { searchResults: [] }; } showResults(response){ this.setState({ searchResults: response.results ...

Teacher Class: class Teacher { private String name; private double salary; private String subject; public Teacher (String tname) { name = tname; } public String getName() { return name; } private double getSal...

DispatchSemaphore provides an efficient implementation of a traditional counting semaphore, which can be used to control access to a resource across multiple execution contexts. A scenario for when to use a semaphore could be if you are doing some file reading/writing, if multiple tasks are t...

There are two main functions in Redis (HSET and HMSET) for adding fields to a hash key. Both functions are available in redis-py. Using HSET: import redis r = redis.StrictRedis(host='myserver', port=6379, db=0) r.hset('my_key', 'field0', 'value0') Using HMSET: import redis r = redis.St...

Swift 3 Serial Queue func serialQueues () { let serialQueue = DispatchQueue(label: "com.example.serial") //default queue type is a serial queue let start = Date () for i in 0...3 { //launch a bunch of tasks serialQueue.a...

This example echoes the special character ! into a file. This would only work when DelayedExpansion is disabled. When delayed expansion in enabled, you will need to use three carets and an exclamation mark like this: @echo off setlocal enabledelayedexpansion echo ^^^!>file echo ^>>&...

Redis allows you to add items to either the right or the left of a list. If I was working with a list, my_list and I wanted to prepend 3 to the list, I could do that using the Redis LPUSH command: LPUSH my_list 3 If I wanted to append 3 to my_list, I would instead use the RPUSH command: RPUSH ...

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 size of a set can be determined using the SCARD command. SCARD will return the cardinality of a set or the number of members in the set. For example, if I had a Redis set my_set stored in the database that looked like (Apple, Orange, Banana), I could get the size using the following code: SCA...

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...

You can enhance your kernel by adding new I/O schedulers if needed. Globally, governors and schedulers are the same; they both provide a way how the system should work. However, for the schedulers it is all about the input/output datastream except for the CPU settings. I/O schedulers decide how an u...

The size of a Redis list can be deterimed using the LLEN command. If I have a four element list stored at the key my_list, I can get the size using: LLEN my_list which will return 4. If a user specifies a key that doesn't exist to LLEN, it will return a zero, but if a key is used that points t...

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...

/** * Resizes an image using a Graphics2D object backed by a BufferedImage. * @param srcImg - source image to scale * @param w - desired width * @param h - desired height * @return - the new resized image */ private BufferedImage getScaledImage(Image srcImg, int w, int h){ //Cre...

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 ...