Category: 04. Dart

Every webpage resides inside a browser window which can be considered as an object. A Document object represents the HTML document that is displayed in that window. The Document object has various properties that refer to other objects which allow access to and modification of document content. The way a document content is accessed and modified is…

Unit Testing involves testing every individual unit of an application. It helps the developer to test small functionalities without running the entire complex application. The Dart external library named “test” provides a standard way of writing and running unit tests. Dart unit testing involves the following steps − Step 1: Installing the “test” package To installing third-party…

Concurrency is the execution of several instruction sequences at the same time. It involves performing more than one task simultaneously. Dart uses Isolates as a tool for doing works in parallel. The dart:isolate package is Dart’s solution to taking single-threaded Dart code and allowing the application to make greater use of the hard-ware available. Isolates, as the name suggests, are…

An asynchronous operation executes in a thread, separate from the main application thread. When an application calls a method to perform an operation asynchronously, the application can continue executing while the asynchronous method performs its task. Example Let’s take an example to understand this concept. Here, the program accepts user input using the IO library. The readLineSync() is a synchronous method. This…

A library in a programming language represents a collection of routines (set of programming instructions). Dart has a set of built-in libraries that are useful to store routines that are frequently used. A Dart library comprises of a set of classes, constants, functions, typedefs, properties, and exceptions. Importing a library Importing makes the components in…

A typedef, or a function-type alias, helps to define pointers to executable code within memory. Simply put, a typedef can be used as a pointer that references a function. Given below are the steps to implement typedefs in a Dart program. Step 1: Defining a typedef A typedef can be used to specify a function signature that we want specific functions to…

Every now and then, developers commit mistakes while coding. A mistake in a program is referred to as a bug. The process of finding and fixing bugs is called debugging and is a normal part of the development process. This section covers tools and techniques that can help you with debugging tasks. The WebStorm editor…

An exception (or exceptional event) is a problem that arises during the execution of a program. When an Exception occurs the normal flow of the program is disrupted and the program/Application terminates abnormally. Built-in Dart exceptions include − Sr.No Exceptions & Description 1 DeferredLoadExceptionThrown when a deferred library fails to load. 2 FormatExceptionException thrown when…

A package is a mechanism to encapsulate a group of programming units. Applications might at times need integration of some third-party libraries or plugins. Every language has a mechanism for managing external packages like Maven or Gradle for Java, Nuget for .NET, npm for Node.js, etc. The package manager for Dart is pub. Pub helps to…

Dart is an optionally typed language. Collections in Dart are heterogeneous by default. In other words, a single Dart collection can host values of various types. However, a Dart collection can be made to hold homogenous values. The concept of Generics can be used to achieve the same. The use of Generics enforces a restriction on…