Tutorial by Examples: er

Arrays You can iterate over nested arrays: [[1, 2], [3, 4]].each { |(a, b)| p "a: #{ a }", "b: #{ b }" } The following syntax is allowed too: [[1, 2], [3, 4]].each { |a, b| "a: #{ a }", "b: #{ b }" } Will produce: "a: 1" "b: 2" ...

Equivalently, we can use the $inject property annotation to achieve the same as above: var MyController = function($scope) { // ... } MyController.$inject = ['$scope']; myModule.controller('MyController', MyController);

.' is the correct way to transpose a vector or matrix in MATLAB. ' is the correct way to take the complex conjugate transpose (a.k.a. Hermitian conjugate) of a vector or matrix in MATLAB. Note that for the transpose .', there is a period in front of the apostrophe. This is in keeping with the ...

Match any: Must match at least one string. In this example the product type must be either 'electronics', 'books', or 'video'. SELECT * FROM purchase_table WHERE product_type LIKE ANY ('electronics', 'books', 'video'); Match all (must meet all requirements). In this example both 'united...

Once the instance of the BackgroundWorker has been declared, it must be given properties and event handlers for the tasks it performs. /* This is the backgroundworker's "DoWork" event handler. This method is what will contain all the work you wish to have your progra...

This allows the BackgroundWorker to be cancelled in between tasks bgWorker.WorkerSupportsCancellation = true; This allows the worker to report progress between completion of tasks... bgWorker.WorkerReportsProgress = true; //this must also be used in conjunction with the ProgressChanged event...

A BackgroundWorker is commonly used to perform tasks, sometimes time consuming, without blocking the UI thread. // BackgroundWorker is part of the ComponentModel namespace. using System.ComponentModel; namespace BGWorkerExample { public partial class ExampleForm : Form { ...

The following example demonstrates the use of a BackgroundWorker to update a WinForms ProgressBar. The backgroundWorker will update the value of the progress bar without blocking the UI thread, thus showing a reactive UI while work is done in the background. namespace BgWorkerExample { public...

Python supports a translate method on the str type which allows you to specify the translation table (used for replacements) as well as any characters which should be deleted in the process. str.translate(table[, deletechars]) ParameterDescriptiontableIt is a lookup table that defines the mappin...

Properties can be added with categories using associated objects, a feature of the Objective-C runtime. Note that the property declaration of retain, nonatomic matches the last argument to objc_setAssociatedObject. See Attach object to another existing object for explanations. #import <objc/run...

Imports System.Reflection Public Class PropertyExample Public Function GetMyProperties() As PropertyInfo() Dim objProperties As PropertyInfo() objProperties = Me.GetType.GetProperties(BindingFlags.Public Or BindingFlags.Instance) Return objProperties End Fun...

As Handlers are used to send Messages and Runnables to a Thread's message queue it's easy to implement event based communication between multiple Threads. Every Thread that has a Looper is able to receive and process messages. A HandlerThread is a Thread that implements such a Looper, for example th...

Naming Convention Notifications are identified by global NSString objects whose names are composed in this way: Name of associated class + Did | Will + UniquePartOfName + Notification For example: NSApplicationDidBecomeActiveNotification NSWindowDidMiniaturizeNotification NSTextViewDidChange...

Swift 2.3 //Remove observer for single notification NSNotificationCenter.defaultCenter().removeObserver(self, name: "TestNotification", object: nil) //Remove observer for all notifications NotificationCenter.defaultCenter().removeObserver(self) Swift 3 //Remove observer for s...

Swift func testNotification(notification: NSNotification) { let userInfo = notification.userInfo let myObject: MyObject = userInfo["someKey"] } Objective-C - (void)testNotification:(NSNotification *)notification { NSDictionary *userInfo = notification.userInfo; My...

#You can use pattern matching to run different #functions based on which parameters you pass #This example uses pattern matching to start, #run, and end a recursive function defmodule Counter do def count_to do count_to(100, 0) #No argument, init with 100 end def ...

Creating a DB and a Table DROP DATABASE IF EXISTS books_db; CREATE DATABASE books_db WITH ENCODING='UTF8' TEMPLATE template0; DROP TABLE IF EXISTS books; CREATE TABLE books ( id SERIAL PRIMARY KEY, client TEXT NOT NULL, data JSONb NOT NULL ); Populating the DB INSERT INTO books...

p { margin:1px; /* 1px margin in all directions */ /*equals to:*/ margin:1px 1px; /*equals to:*/ margin:1px 1px 1px; /*equals to:*/ margin:1px 1px 1px 1px; } Another exapmle: p{ margin:10px 15px; /...

g$ The above matches one letter (the letter g) at the end of a string in most regex engines (not in Oniguruma, where the $ anchor matches the end of a line by default, and the m (MULTILINE) modifier is used to make a . match any characters including line break characters, as a DOTALL modifier in ...

You can use subqueries to define a temporary table and use it in the FROM clause of an "outer" query. SELECT * FROM (SELECT city, temp_hi - temp_lo AS temp_var FROM weather) AS w WHERE temp_var > 20; The above finds cities from the weather table whose daily temperature variation i...