Tutorial by Examples: w

Python makes it very simple to check whether an item is in a list. Simply use the in operator. lst = ['test', 'twest', 'tweast', 'treast'] 'test' in lst # Out: True 'toast' in lst # Out: False Note: the in operator on sets is asymptotically faster than on lists. If you need to use it ...

Standard installation All Node.js binaries, installers, and source files can be downloaded here. You can download just the node.exe runtime or use the Windows installer (.msi), which will also install npm, the recommended package manager for Node.js, and configure paths. Installation by package m...

Users of homebrew can install gradle by running brew install gradle

Users of SdkMan can install Gradle by running: sdk install gradle Install specific version sdk list gradle sdk install gradle 2.14 Switch versions sdk use gradle 2.12

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...

Use the rel="alternate" attribute to allow discoverability of your Atom/RSS feeds. <link rel="alternate" type="application/atom+xml" href="http://example.com/feed.xml" /> <link rel="alternate" type="application/rss+xml" href=&quo...

HTML <input type="range"></input> CSS EffectPseudo SelectorThumbinput[type=range]::-webkit-slider-thumb, input[type=range]::-moz-range-thumb, input[type=range]::-ms-thumbTrackinput[type=range]::-webkit-slider-runnable-track, input[type=range]::-moz-range-track, input[type=...

When working on a project, you might be half-way through a feature branch change when a bug is raised against master. You're not ready to commit your code, but you also don't want to lose your changes. This is where git stash comes in handy. Run git status on a branch to show your uncommitted chang...

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...

A simple switch statement: switch a + b { case c: // do something case d: // do something else default: // do something entirely different } The above example is equivalent to: if a + b == c { // do something } else if a + b == d { // do something else } else { ...

iex(1)> a = 10 10 iex(2)> b = 20 20 iex(3)> a + b 30 You can get a specific row passing the index of the row: iex(4)> v(3) 30 You can also specify an index relative to the current row: iex(5)> v(-1) # Retrieves value of row (5-1) -> 4 30 iex(6)> v(-5) # Retrieves...

The while operator iterates over a block of code until the conditional query equals false or the code is interrupted with a goto, return, break or throw statement. Syntax for while keyword: while( condition ) { code block; } Example: int i = 0; while (i++ < 5) { Console.WriteLine...

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)...

With this example, we will see how to load a color image from disk and display it using OpenCV's built-in functions. We can use the C/C++, Python or Java bindings to accomplish this. In C++: #include <opencv2/core.hpp> #include <opencv2/highgui.hpp> #include <iostream> usi...

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...

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...

Ruby extends the standard group syntax (...) with a named group, (?<name>...). This allows for extraction by name instead of having to count how many groups you have. name_reg = /h(i|ello), my name is (?<name>.*)/i #i means case insensitive name_input = "Hi, my name is Zaphod Be...

The data.table package introduces the function fread. While it is similar to read.table, fread is usually faster and more flexible, guessing the file's delimiter automatically. # get the file path of a CSV included in R's utils package csv_path <- system.file("misc", "exDIF.csv&q...

Create a XIB file Xcode Menu Bar > File > New > File. Select iOS, User Interface and then "View": Give your XIB a name (yes, we are doing a Pokemon example 👾). Remember to check your target and hit "Create". Design your view To make things easier, set:...