Tutorial by Examples: ga

Manually open and close a file. # Using new method f = File.new("test.txt", "r") # reading f = File.new("test.txt", "w") # writing f = File.new("test.txt", "a") # appending # Using open method f = open("test.txt", "r&...

For immutable elements (e.g. None, string literals etc.): my_list = [None] * 10 my_list = ['test'] * 10 For mutable elements, the same construct will result in all elements of the list referring to the same object, for example, for a set: >>> my_list=[{1}] * 10 >>> print(my_...

General syntax: DATEADD (datepart , number , datetime_expr) To add a time measure, the number must be positive. To subtract a time measure, the number must be negative. Examples DECLARE @now DATETIME2 = GETDATE(); SELECT @now; --2016-07-21 14:39:46.4170000 SELECT DAT...

Sometimes when destructuring maps, you would like to bind the destructured values to their respective key name. Depending on the granularity of the data structure, using the standard destructuring scheme may be a little bit verbose. Let's say, we have a map based record like so : (def john {:lastn...

Using .NET's rich reflection APIs, you can gain access to an assembly's metadata. For example, you can get this assembly's title attribute with the following code using System.Linq; using System.Reflection; ... Assembly assembly = typeof(this).Assembly; var titleAttribute = assembly.GetCust...

This example shows how a MongoDB collection can be displayed in a React component. The collection is continuously synchronized between server and client, and the page instantly updates as database contents change. To connect React components and Meteor collections, you'll need the react-meteor-data...

In Swift you can easily separate a String into an array by slicing it at a certain character: 3.0 let startDate = "23:51" let startDateAsArray = startDate.components(separatedBy: ":") // ["23", "51"]` 2.2 let startDate = "23:51" let sta...

Sorting arrays can be easily done with the Arrays api. import java.util.Arrays; // creating an array with integers int[] array = {7, 4, 2, 1, 19}; // this is the sorting part just one function ready to be used Arrays.sort(array); // prints [1, 2, 4, 7, 19] System.out.println(Arrays.toString...

We try to extract imdb top chart movies and ratings R> library(RCurl) R> library(XML) R> url <- "http://www.imdb.com/chart/top" R> top <- getURL(url) R> parsed_top <- htmlParse(top, encoding = "UTF-8") R> top_table <- readHTMLTable(parsed_top)[...

When you also want to expose metadata without a config file you can build on the example programmatically creating a ServiceHost: public ConsoleHost() { mHost = new ServiceHost(typeof(Example), new Uri("http://localhost:8000/Example"), new Uri("net.tcp://9000/Example")); ...

You can also perform this task recursively, but I have chosen in this example to use an iterative approach. This task is useful if you are inserting all of your nodes at the beginning of a linked list. Here is an example: #include <stdio.h> #include <stdlib.h> #define NUM_ITEMS 10...

Methods are defined with the def keyword, followed by the method name and an optional list of parameter names in parentheses. The Ruby code between def and end represents the body of the method. def hello(name) "Hello, #{name}" end A method invocation specifies the method name, the...

To create an albums collection, add the following to your config.yml file: collections: - albums Create a corresponding folder at the root of your Jekyll install, named exactly what you put in your config.yml file with an additional prepended underscore; in our example, <source>/_albums....

These Java issues can be very embarrassing, and sometimes remain undiscovered until run in production. Fallthrough behavior in switch statements is often useful; however, missing a “break” keyword when such behavior is not desired can lead to disastrous results. If you have forgotten to put a “break...

Amp harnesses Promises [another name for Awaitables] and Generators for coroutine creation. require __DIR__ . '/vendor/autoload.php'; use Amp\Dns; // Try our system defined resolver or googles, whichever is fastest function queryStackOverflow($recordtype) { $requests = [ Dns\qu...

This example shows how to establish a connection to an SSL-enabled POP3 email server and send a simple (text only) email. // Configure mail provider Properties props = new Properties(); props.put("mail.smtp.host", "smtp.mymailprovider.com"); props.put("ma...

Once you've installed the .NET CLI tools, you can create a new project with the following command: dotnet new --lang f# This creates a command line program.

A shallow copy is a copy of a collection without performing a copy of its elements. >>> import copy >>> c = [[1,2]] >>> d = copy.copy(c) >>> c is d False >>> c[0] is d[0] True

If you have nested lists, it is desireable to clone the nested lists as well. This action is called deep copy. >>> import copy >>> c = [[1,2]] >>> d = copy.deepcopy(c) >>> c is d False >>> c[0] is d[0] False

You can create shallow copies of lists using slices. >>> l1 = [1,2,3] >>> l2 = l1[:] # Perform the shallow copy. >>> l2 [1,2,3] >>> l1 is l2 False