Tutorial by Topics: ons

Constructors are methods in a class that are invoked when an instance of that class is created. Their main responsibility is to leave the new object in a useful and consistent state. Destructors/Finalizers are methods in a class that are invoked when an instance of that is destroyed. In C# they are...

There are several kinds of collection: Array List Queue SortedList Stack Dictionary

Related: MSDN: Exceptions and Exception Handling (C# Programming Guide) MSDN: Handling and Throwing Exceptions MSDN: CA1031: Do not catch general exception types MSDN: try-catch (C# Reference)

A lambda expression is a syntax for creating anonymous functions inline. More formally, from the C# Programming Guide: A lambda expression is an anonymous function that you can use to create delegates or expression tree types. By using lambda expressions, you can write local functions that can ...

Objects of type Throwable and its subtypes can be sent up the stack with the throw keyword and caught with try…catch statements. void someMethod() throws SomeException { } //method declaration, forces method callers to catch if SomeException is a checked exception type try { someMethod();...

The collections framework in java.util provides a number of generic classes for sets of data with functionality that can't be provided by regular arrays. Collections framework contains interfaces for Collection<O>, with main sub-interfaces List<O> and Set<O>, and mapping collectio...

Lambda expressions provide a clear and concise way of implementing a single-method interface using an expression. They allow you to reduce the amount of code you have to create and maintain. While similar to anonymous classes, they have no type information by themselves. Type inference needs to happ...

Note that a ViewTreeObserver instance associated with a View instance can become invalid while that View is still alive. From the View.getViewTreeObserver javadocs: // The returned ViewTreeObserver observer is not guaranteed to remain // valid for the lifetime of this View. If the caller of this...

A singleton is a class that only ever has one single instance. For more information on the Singleton design pattern, please refer to the Singleton topic in the Design Patterns tag.

A regular expression is a special sequence of characters that helps in matching or finding other strings or sets of strings, using a specialized syntax held in a pattern. Java has support for regular expression usage through the java.util.regex package. This topic is to introduce and help developers...

This documentation page is for showing details with example about java class constructors and about Object Class Methods which are automatically inherited from the superclass Object of any newly created class. public final native Class<?> getClass() public final native void notify() pu...

In Java, an annotation is a form of syntactic metadata that can be added to Java source code. It provides data about a program that is not part of the program itself. Annotations have no direct effect on the operation of the code they annotate. Classes, methods, variables, parameters and packages ar...

An Android application needs to run on all kinds of devices. Each device may have a different version on Android running on it. Now, each Android version might not support all the features that your app requires, and so while building an app, you need to keep the minimum and maximum Android version...

JavaScriptSerializer vs Json.NET The JavaScriptSerializer class was introducted in .NET 3.5 and is used internally by .NET's asynchronous communication layer for AJAX-enabled applications. It can be used to work with JSON in managed code. Despite the existence of the JavaScriptSerializer class,...

Functions in JavaScript provide organized, reusable code to perform a set of actions. Functions simplify the coding process, prevent redundant logic, and make code easier to follow. This topic describes the declaration and utilization of functions, arguments, parameters, return statements and scope ...

List comprehensions in Python are concise, syntactic constructs. They can be utilized to generate lists from other lists by applying functions to each element in the list. The following section explains and demonstrates the use of these expressions. [x + 1 for x in (1, 2, 3)] # list comprehen...

When using boolean coercion, the following values are considered "falsy": false 0 "" (empty string) null undefined NaN (not a number, e.g. 0/0) document.all¹ (browser context) Everything else is considered "truthy". ¹ willful violation of the ECMAScript ...