Tutorial by Examples: at

Starting with a given list a: a = [1, 2, 3, 4, 5] append(value) – appends a new element to the end of the list. # Append values 6, 7, and 7 to the list a.append(6) a.append(7) a.append(7) # a: [1, 2, 3, 4, 5, 6, 7, 7] # Append another list b = [8, 9] a.append(b) # a: [1, 2, 3, 4, ...

Due to auto unboxing, one can use a Boolean in an if statement: Boolean a = Boolean.TRUE; if (a) { // a gets converted to boolean System.out.println("It works!"); } That works for while, do while and the condition in the for statements as well. Note that, if the Boolean is null...

Syntax for accessing rows and columns: [, [[, and $ This topic covers the most common syntax to access specific rows and columns of a data frame. These are Like a matrix with single brackets data[rows, columns] Using row and column numbers Using column (and row) names Like a list: Wi...

Annotation types are defined with @interface. Parameters are defined similar to methods of a regular interface. @interface MyAnnotation { String param1(); boolean param2(); int[] param3(); // array parameter } Default values @interface MyAnnotation { String param1() defau...

Switch statements compare the value of an expression against 1 or more values and executes different sections of code based on that comparison. var value = 1; switch (value) { case 1: console.log('I will always run'); break; case 2: console.log('I will never run'); break;...

Posting form data fetch(`/example/submit`, { method: 'POST', body: new FormData(document.getElementById('example-form')) }); Posting JSON data fetch(`/example/submit.json`, { method: 'POST', body: JSON.stringify({ email: document.getElementById('example-email').val...

The first argument of re.match() is the regular expression, the second is the string to match: import re pattern = r"123" string = "123zzb" re.match(pattern, string) # Out: <_sre.SRE_Match object; span=(0, 3), match='123'> match = re.match(pattern, string) ma...

Make sure you see Registering for local notifications in order for this to work: Swift let notification = UILocalNotification() notification.alertBody = "Hello, local notifications!" notification.fireDate = NSDate().dateByAddingTimeInterval(10) // 10 seconds after now UIApplication.sh...

iOS 8 In order to present local notifications to the user, you have to register your app with the device: Swift let settings = UIUserNotificationSettings(forTypes: [.Badge, .Sound, .Alert], categories: nil) UIApplication.sharedApplication().registerUserNotificationSettings(settings) Objective...

Steam has a games under $10 section of their store page. Somewhere deep in the heart of their systems, there's probably a query that looks something like: SELECT * FROM Items WHERE Price < 10

The Basics The simplist way to convert one date format into another is to use strtotime() with date(). strtotime() will convert the date into a Unix Timestamp. That Unix Timestamp can then be passed to date() to convert it to the new format. $timestamp = strtotime('2008-07-01T22:35:17.02'); $new_...

MATLAB allows for several methods to index (access) elements of matrices and arrays: Subscript indexing - where you specify the position of the elements you want in each dimension of the matrix separately. Linear indexing - where the matrix is treated as a vector, no matter its dimensions. That ...

re.findall(r"[0-9]{2,3}", "some 1 text 12 is 945 here 4445588899") # Out: ['12', '945', '444', '558', '889'] Note that the r before "[0-9]{2,3}" tells python to interpret the string as-is; as a "raw" string. You could also use re.finditer() which works in...

To create a variable in Python, all you need to do is specify the variable name, and then assign a value to it. <variable name> = <value> Python uses = to assign values to variables. There's no need to declare a variable in advance (or to assign a data type to it), assigning a value ...

Install the svn client to start collaborating on the project that is using Subversion as its version control system. To install Subversion, you can build it yourself from a source code release or download a binary package pre-built for your operating system. The list of sites where you can obtain a...

In most environments, console.table() can be used to display objects and arrays in a tabular format. For example: console.table(['Hello', 'world']); displays like: (index)value0"Hello"1"world" console.table({foo: 'bar', bar: 'baz'}); displays like: (index)value"fo...

RGB is an additive color model which represents colors as mixtures of red, green, and blue light. In essence, the RGB representation is the decimal equivalent of the Hexadecimal Notation. In Hexadecimal each number ranges from 00-FF which is equivalent to 0-255 in decimal and 0%-100% in percentages....

HSL stands for hue ("which color"), saturation ("how much color") and lightness ("how much white"). Hue is represented as an angle from 0° to 360° (without units), while saturation and lightness are represented as percentages. p { color: hsl(240, 100%, 50%); /* B...

The Edges The browser creates a rectangle for each element in the HTML document. The Box Model describes how the padding, border, and margin are added to the content to create this rectangle. Diagram from CSS2.2 Working Draft The perimeter of each of the four areas is called an edge. Each edge ...

The @property decorator can be used to define methods in a class which act like attributes. One example where this can be useful is when exposing information which may require an initial (expensive) lookup and simple retrieval thereafter. Given some module foobar.py: class Foo(object): def __...