Tutorial by Examples: g

The next function is useful even without iterating. Passing a generator expression to next is a quick way to search for the first occurrence of an element matching some predicate. Procedural code like def find_and_transform(sequence, predicate, func): for element in sequence: if predi...

If you want to change an attribute of a control such as a textbox or label from another thread than the GUI thread that created the control, you will have to invoke it or else you might get an error message stating: "Cross-thread operation not valid: Control 'control_name' accessed from a th...

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...

$string = "a;b;c\nd;e;f"; // $1, $2 and $3 represent the first, second and third capturing groups echo preg_replace("(^([^;]+);([^;]+);([^;]+)$)m", "$3;$2;$1", $string); Outputs c;b;a f;e;d Searches for everything between semicolons and reverses the order.

// 1. Instantiate an AlertDialog.Builder with its constructor // the parameter this is the context (usually your activity) AlertDialog.Builder builder = new AlertDialog.Builder(this); // 2. Chain together various setter methods to set the dialog characteristics builder.SetMessage(Resource.Str...

HBase Standalone is a mode which allow you to get rid of HDFS and to test HBase before deploying in a cluster, It is not production oriented. Installing HBase in standalone is extremely simple. First you have to download the HBase archive named hbase-X.X.X-bin.tar.gz available on one of the apache ...

In performing parsing, before starting, the grammar for the language needs to be specified. A source of tokens is also needed for the parser. The parser could be hand-written code, or a parser generator tool could be used. If a parser generator tool is used, then that tool will need to be downloade...

If you need to send events from fragment to activity, one of the possible solutions is to define callback interface and require that the host activity implement it. Example Send callback to an activity, when fragment's button clicked First of all, define callback interface: public interface Samp...

This is an example for how to handle dynamic key for response. Here A and B are dynamic keys it can be anything Response { "response": [ { "A": [ { "name": "Tango" }, { "name": "P...

The ToString method on an enum returns the string name of the enumeration. For instance: Module Module1 Enum Size Small Medium Large End Enum Sub Main() Dim shirtSize As Size = Size.Medium Dim output As String = shirtSize.ToString() ...

Some common operations in MATLAB, like differentiation or integration, output results that have a different amount of elements than the input data has. This fact can easily be overlooked, which would usually cause errors like Matrix dimensions must agree. Consider the following example: t = 0:0.1:1...

You can use parfor to execute the iterations of a loop in parallel: Example: poolobj = parpool(2); % Open a parallel pool with 2 workers s = 0; % Performing some parallel Computations parfor i=0:9 s = s + 1; end disp(s) % Outputs '10' d...

You can use the $q.all function to call a .then method after an array of promises has been successfully resolved and fetch the data they resolved with. Example: JS: $scope.data = [] $q.all([ $http.get("data.json"), $http.get("more-data.json"), ]).then(funct...

The $q constructor function is used to create promises from asynchronous APIs that use callbacks to return results. $q(function(resolve, reject) {...}) The constructor function receives a function that is invoked with two arguments, resolve and reject that are functions which are used to eithe...

var pug = require('pug'); // compile var fn = pug.compile('string of pug', options); var html = fn(locals); // render var html = pug.render('string of pug', merge(options, locals)); // renderFile var html = pug.renderFile('filename.pug', merge(options, locals)); Options filename U...

When using C#'s inbuilt lock statement an instance of some type is needed, but its state does not matter. An instance of object is perfect for this: public class ThreadSafe { private static readonly object locker = new object(); public void SomeThreadSafeMethod() { lock (locker) { ...

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....

Even experienced Java developers tend to think that Java has only three protection modifiers. The language actually has four! The package private (a.k.a. default) level of visibility is often forgotten. You should pay attention to what methods you make public. The public methods in an application a...

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...

Every time a program opens a resource, such as a file or network connection, it is important to free the resource once you are done using it. Similar caution should be taken if any exception were to be thrown during operations on such resources. One could argue that the FileInputStream has a finaliz...