Tutorial by Examples: rom

Not always we have liberty to read from or write to a local system path. For example if R code streaming map-reduce must need to read and write to file connection. There can be other scenarios as well where one is going beyond local system and with advent of cloud and big data, this is becoming incr...

static void testNumericPromotion() { char char1 = 1, char2 = 2; short short1 = 1, short2 = 2; int int1 = 1, int2 = 2; float float1 = 1.0f, float2 = 2.0f; // char1 = char1 + char2; // Error: Cannot convert from int to char; // short1 = short1 + short2; // Err...

You can read an a binary file using this piece of code in all recent versions of Java: Java SE 1.4 File file = new File("path_to_the_file"); byte[] data = new byte[(int) file.length()]; DataInputStream stream = new DataInputStream(new FileInputStream(file)); stream.readFully(data); s...

A String can be read from an InputStream using the byte array constructor. import java.io.*; public String readString(InputStream input) throws IOException { byte[] bytes = new byte[50]; // supply the length of the string in bytes here input.read(bytes); return new String(bytes); ...

- removeObjectForKey: Removes a given key and its associated value from the dictionary. NSMutableDictionary *dict = [NSMutableDictionary dictionaryWithDictionary:@{@"key1":@"Easy",@"key2": @"Tutorials"}]; [dict removeObjectForKey:@"key1"]; NSLog...

Dim sites() As String = {"Stack Overflow", "Super User", "Ask Ubuntu", "Hardware Recommendations"} Dim query = From x In sites Where x.StartsWith("S") ' result = "Stack Overflow", "Super User" Query will be enumerable objec...

Public Function GetUserFirstName(UserName As String) As String Dim Firstname As String = "" 'Specify the SQL that you want to use including a Parameter Dim SQL As String = "select firstname from users where username=@UserName" 'Provide a Data Sourc...

// Checks a string to see if it is a palindrome bool function IsPalindrome(string input) { if (input.size() <= 1) { return true; } else if (input[0] == input[input.size() - 1]) { return IsPalindrome(input.substr(1,input.size() - 2)); } else { r...

In many instances, you will want to send data from the R server to the JS client. Here is a very simple example: library(shiny) runApp( list( ui = fluidPage( tags$script( "Shiny.addCustomMessageHandler('message', function(params) { alert(params); });" ), ...

The function angular.fromJson will deserialize a valid JSON string and return an Object or an Array. angular.fromJson(string|object) Note that this function is not limited to only strings, it will output a representation of any object passed to it. Examples: angular.fromJson("{\"yo...

Downloading a file from the internet is a very common task required by almost every application your likely to build. To accomplish this, you can use the "System.Net.WebClient" class. The simplest use of this, using the "using" pattern, is shown below: using (var webClient = n...

User Prompts are methods part of the Web Application API used to invoke Browser modals requesting a user action such as confirmation or input. window.alert(message) Show a modal popup with a message to the user. Requires the user to click [OK] to dismiss. alert("Hello World"); More...

When using prompt a user can always click Cancel and no value will be returned. To prevent empty values and make it more persistent: <h2>Welcome <span id="name"></span>!</h2> <script> // Persistent Prompt modal var userName; while(!userName) { userN...

FROM <image> Or FROM <image>:<tag> Or FROM <image>@<digest> The FROM instruction sets the Base Image for subsequent instructions. As such, a valid Dockerfile must have FROM as its first instruction. The image can be any valid image – it is especially easy to ...

Mesos is a cluster manager aiming for improved resource utilization by dynamically sharing resources among multiple frameworks. It was started at the University of California, Berkeley in 2009 and is in production use in many companies, including Twitter and Airbnb. It became an Apache top-level ...

docker network disconnect app-backend myAwesomeApp-1 This command detaches the myAwesomeApp-1 container from the app-backend network. The container will no longer be able to communicate with other containers on the network it has been disconnected from, nor use the embedded DNS resolver to look u...

While attached to a running container with a pty assigned (docker run -it ...), you can press ControlP - ControlQ to detach.

Prompt will display a dialog to the user requesting their input. You can provide a message that will be placed above the text field. The return value is a string representing the input provided by the user. var name = prompt("What's your name?"); console.log("Hello, " + name); ...

C++11 struct info_type { std::string name; int age; float height; // we define an overload of operator>> as a friend function which // gives in privileged access to private data members friend std::istream& operator>>(std::istream& is, info_...

Disclaimer: the examples presented here are only for the purpose of showing the use of abstract classes and inheritance and may not necessarily be of a practical use. Also, there is no sich thing as polymorphic in MATLAB and therefore the use of abstract classes is limited. This example is to show w...