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Sometimes, you need to work with an array while ensuring you don't modify the original. Instead of a clone method, arrays have a slice method that lets you perform a shallow copy of any part of an array. Keep in mind that this only clones the first level. This works well with primitive types, like n...

Sometimes it's necessary to convert a Discriminated Union to and from a string: module UnionConversion open Microsoft.FSharp.Reflection let toString (x: 'a) = match FSharpValue.GetUnionFields(x, typeof<'a>) with | case, _ -> case.Name let fromStri...

Big-O notation is a notation used to talk about the long-term growth rates of functions. It's often used in the analysis of algorithms to talk about the runtime of an algorithm or related concepts like space complexity. In common usage, big-O notation is used to talk about how an algorithm's runtim...

1. Install Node.js and NPM: Gulp requires Node.js and NPM, Node's package manager. Most installers include NPM with Node.js. Refer to the installation documentation or confirm it is already installed by running the following command in your terminal, npm -v // will return NPM version or error say...

The order of keys in Python dictionaries is arbitrary: they are not governed by the order in which you add them. For example: >>> d = {'foo': 5, 'bar': 6} >>> print(d) {'foo': 5, 'bar': 6} >>> d['baz'] = 7 >>> print(a) {'baz': 7, 'foo': 5, 'bar': 6} >&g...

This example comes from the official document. Suppose you have a python application using redis as backend. After writing Dockerfile, create a docker-compose.yml file like this: version: '2' services: web: build: . ports: - "5000:5000" volumes: - .:/code ...

Floating point numbers of type real cannot have any real value. They can represent real numbers up to certain amount of decimal digits. FORTRAN 77 guaranteed two floating point types and more recent standards guarantee at least two real types. Real variables may be declared as real x double prec...

This example shows how to create a simple notification that starts an application when the user clicks it. Specify the notification's content: NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(this) .setSmallIcon(R.drawable.ic_launcher) // notification icon .se...

All these are shell commands. docker-machine env to get the current default docker-machine configuration eval $(docker-machine env) to get the current docker-machine configuration and set the current shell environment up to use this docker-machine with . If your shell is set up to use a proxy, yo...

You can set the opacity to a certain UIColor without creating a new one using the init(red:_,green:_,blue:_,alpha:_) initializer. Swift let colorWithAlpha = UIColor.redColor().colorWithAlphaComponent(0.1) Swift 3 //In Swift Latest Version _ colorWithAlpha = UIColor.red.withAlphaComponent(0.1)...

The following code is based on the examples provided by the documentation on std::net::TcpListener. This server application will listen to incoming requests and send back all incoming data, thus acting as an "echo" server. The client application will send a small message and expect a reply...

The following (trivial) example function simply returns the constant INT value 12. DELIMITER || CREATE FUNCTION functionname() RETURNS INT BEGIN RETURN 12; END; || DELIMITER ; The first line defines what the delimiter character(DELIMITER ||) is to be changed to, this is needed to be s...

This code example creates a TCP client, sends "Hello World" over the socket connection, and then writes the server response to the console before closing the connection. // Declare Variables string host = "stackoverflow.com"; int port = 9999; int timeout = 5000; // Create ...

prop_evenNumberPlusOneIsOdd :: Integer -> Property prop_evenNumberPlusOneIsOdd x = even x ==> odd (x + 1) If you want to check that a property holds given that a precondition holds, you can use the ==> operator. Note that if it's very unlikely for arbitrary inputs to match the precondit...

A try/catch block is used to catch exceptions. The code in the try section is the code that may throw an exception, and the code in the catch clause(s) handles the exception. #include <iostream> #include <string> #include <stdexcept> int main() { std::string str("foo&...

You can make an UILabel with a dynamic height using auto layout. You need to set the numberOfLines to zero (0), and add a minimal height by setting up a constraints with a relation of type .GreaterThanOrEqual on the .Height attribute iOS 6 Swift label.numberOfLines = 0 let heightConstraint = ...

Assumptions: An Oracle JDK has been installed. The JDK was installed to the default directory. Setup steps Open Windows Explorer. In the navigation pane on the left right click on This PC (or Computer for older Windows versions). There is a shorter way without using the explorer in...

Array iteration comes in two flavors, foreach and the classic for-loop: a=(1 2 3 4) # foreach loop for y in "${a[@]}"; do # act on $y echo "$y" done # classic for-loop for ((idx=0; idx < ${#a[@]}; ++idx)); do # act on ${a[$idx]} echo "${a[$idx]}&...

Common mobile-optimized sites use the <meta name="viewport"> tag like this: <meta name="viewport" content="width=device-width, initial-scale=1"> The viewport element gives the browser instructions on how to control the page's dimensions and scaling based...

Assembly language is a human readable form of machine language or machine code which is the actual sequence of bits and bytes on which the processor logic operates. It is generally easier for humans to read and program in mnemonics than binary, octal or hex, so humans typically write code in assemb...