Tutorial by Examples: e

Block Indentation

Python uses indentation to define control and loop constructs. This contributes to Python's readability, however, it requires the programmer to pay close attention to the use of whitespace. Thus, editor miscalibration could result in code that behaves in unexpected ways. Python uses the colon symbo...

Python Language • Getting started with Python Language

Remove, delete and cleanup containers

docker rm can be used to remove a specific containers like this: docker rm <container name or id> To remove all containers you can use this expression: docker rm $(docker ps -qa) By default docker will not delete a container that is running. Any container that is running will produce a...

Docker • Managing containers

normalize.css

Browsers have a default set of CSS styles they use for rendering elements. Some of these styles can even be customised using the browser's settings to change default font face and size definitions, for example. The styles contain the definition of which elements are supposed to be block-level or inl...

CSS • Normalizing Browser Styles

Send text, key pressed and touch events to Android Device via ADB

execute the following command to insert the text into a view with a focus (if it supports text input) 6.0 Send text on SDK 23+ adb shell "input keyboard text 'Paste text on Android Device'" If already connected to your device via adb: input text 'Paste text on Android Device' 6...

Android • adb shell

List packages

Prints all packages, optionally only those whose package name contains the text in <FILTER>. adb shell pm list packages [options] <FILTER> All <FILTER> adb shell pm list packages Attributes: -f to see their associated file. -i See the installer for the packages. -u to ...

Android • adb shell

Reassigning constants

You can't reassign constants. const foo = "bar"; foo = "hello"; Prints: Uncaught TypeError: Assignment to constant.

JavaScript • Declarations and Assignments

Declaring and initializing constants

You can initialize a constant by using the const keyword. const foo = 100; const bar = false; const person = { name: "John" }; const fun = function () = { /* ... */ }; const arrowFun = () => /* ... */ ; Important You must declare and initialize a constant in the same statement....

JavaScript • Declarations and Assignments

Push a specific object to a remote branch

General syntax git push <remotename> <object>:<remotebranchname> Example git push origin master:wip-yourname Will push your master branch to the wip-yourname branch of origin (most of the time, the repository you cloned from). Delete remote branch Deleting the remote br...

Git • Pushing

Granting & revoking API 23+ permissions

A one-liner that helps granting or revoking vulnerable permissions. granting adb shell pm grant <sample.package.id> android.permission.<PERMISSION_NAME> revoking adb shell pm revoke <sample.package.id> android.permission.<PERMISSION_NAME> Granting all run...

Android • adb shell

Space Views Evenly

It is common to want two views to be side by side, centered in their superview. The common answer given on Stack Overflow is to embed these two views in a UIView and center the UIView. This is not necessary or recommended. From the UILayoutGuide docs: There are a number of costs associated with...

iOS • Auto Layout

Hello World

Without JSX Here's a basic example that uses React's main API to create a React element and the React DOM API to render the React element in the browser. <!DOCTYPE html> <html> <head> <meta charset="UTF-8" /> <title>Hello React!</title> ...

React • Getting started with React

Infinity and NaN ("not a number")

In all versions of Python, we can represent infinity and NaN ("not a number") as follows: pos_inf = float('inf') # positive infinity neg_inf = float('-inf') # negative infinity not_a_num = float('nan') # NaN ("not a number") In Python 3.5 and higher, we can also us...

Python Language • Math Module

Iterating over a list

Python supports using a for loop directly on a list: my_list = ['foo', 'bar', 'baz'] for item in my_list: print(item) # Output: foo # Output: bar # Output: baz You can also get the position of each item at the same time: for (index, item) in enumerate(my_list): print('The item i...

Python Language • List

Create a "Please wait..." popup

This code can be added to any event like a listener, button, etc. A blocking JDialog will appear and will remain until the process is complete. final JDialog loading = new JDialog(parentComponent); JPanel p1 = new JPanel(new BorderLayout()); p1.add(new JLabel("Please wait..."), BorderLa...

swing • Basics

Text

The most basic form of data binding is text interpolation using the “Mustache” syntax (double curly braces): <span>Message: {{ msg }}</span> The mustache tag will be replaced with the value of the msg property on the corresponding data object. It will also be updated whenever the dat...

Vue.js • Data Binding

Attributes

Mustaches can also be used inside HTML attributes: <div id="item-{{ id }}"></div> Note that attribute interpolations are disallowed in Vue.js directives and special attributes. Don’t worry, Vue.js will raise warnings for you when mustaches are used in wrong places.

Vue.js • Data Binding

Filters

Vue.js allows you to append optional “filters” to the end of an expression, denoted by the “pipe” symbol: {{ message | capitalize }} Here we are “piping” the value of the message expression through the built-in capitalize filter, which is in fact just a JavaScript function that returns the capit...

Vue.js • Data Binding

Hello World

class Greeter { greeting: string; constructor(message: string) { this.greeting = message; } greet(): string { return this.greeting; } }; let greeter = new Greeter("Hello, world!"); console.log(greeter.greet()); Here we have a class, Gree...

TypeScript • Getting started with TypeScript

Rectangles

You can use the clearRect method to clear any rectangular section of the canvas. // Clear the entire canvas ctx.clearRect(0, 0, canvas.width, canvas.height); Note: clearRect is dependent on the transformation matrix. To deal with this, it's possible to reset the transformation matrix befor...

html5-canvas • Clearing the screen

Installation or Setup

GitHub is a huge collection of Git repositories. In other words, you can think of GitHub as a collection of many projects! Creating An Account Visit GitHub's main page Here Pick a username, enter in your email address, and pick a secure password and you're ready to go! Useful Tools For Git/...

github • Getting started with github