Found 56 Articles for Dart Programming

Dart is a lexically scoped language. Lexically scoped means that as we move downwards to the latest variable declaration, the variable value will depend on the innermost scope in which the variable is present.ExampleConsider the example shown below − Live Demovoid main(){    var language = 'Dart';    void printLanguage(){       language = 'DartLang';       print("Language is ${language}");    }    printLanguage(); }In the above example, we changed the value of the language variable inside the scope of the printLanguage() function and since we are printing the value inside the printLanguage() function, the innermost scope is the one inside ... Read More

Iterator class in Dart is an interface that is used when we want to get items, one at a time, from an object.The iterator is initially positioned before the first element. Before accessing the first element the iterator need to be advanced using the moveNext to point to the first element. If we reached the end of the object then moveNext returns false, and all further calls to moveNext will also return false.It should be noted that if change anything in the object during the iteration, then the behaviour is unspecified.We make use of the current property of the Iterator ... Read More

Iterables in Dart are a collection of values, or "elements", that we can access in a sequential manner.The elements of the iterable are accessed by making use of an iterator getter.There are multiple collections in Dart that implement the Iterables, for example, LinkedList, List, ListQueue, MapKeySet, MapValueSet and much more.There are different constructors that we can make use of when we want to create an Iterable, like −Iterable() - creates an iterableIterable.empty() - creates an empty iterable.Iterable.generate() - creates an iterable which generates its elements dynamically.ExampleLet's consider a few examples of Iterables in Dart.Consider the example shown below − Live Demovoid main(){   ... Read More

Inheritance in dart is defined as the process in which one class derive the properties and characteristics of another class. It is helpful as it provides an ability with which we can create a new class from an existing class.Inheritance is a major component of a programming paradigm known as OOPS (Object-Oriented Programming).With the help of Inheritance, one class can make use of all the properties and characteristics of another class.In general, two classes are required for inheritance and these mainly are −Parent class - A class that is inherited by the other class is known as the parent class. ... Read More

We know that const keyword provides immutability in objects. But what about the cases, where we want the entire class to be immutable in nature.In such cases, we make use of the immutable annotation that is present inside the meta package of dart library.Syntaximport 'pacakge:meta/meta.dart'; @immutable class User {    String name; }It should be noted that once we declare any class with the immutable notation, all its object and the object properties and methods will be immutable as well.ExampleConsider the example shown below − Live Demoimport 'pacakge:meta/meta.dart'; @immutable class User {    final String name;    User(this.name);   ... Read More

Immutability is the ability to remain constant. Whenever we talk about immutability we mention the immutable nature.In object oriented and functional programming, we make use of the immutable nature of objects a lot. Being immutable means that the state of the object cannot be modified after its creation.It is a very important topic these days when we talk about front-end development, as there are several occasions and scenarios where we want to maintain the state and the way to do that is to make use of immutability.In Dart, there are different ways with which we can achieve immutability and sometimes ... Read More

If statements are a major part of any programming language as they allow us to run things based on certain conditions, that's why they come under the conditional statements category.Dart's if-else statements follow the same syntax as Java's ones.Syntaxif( condition ) {    statement }If the condition in the above if parentheses evaluate to true, then the statements inside the code block will be evaluated.ExampleConsider the example shown below − Live Demovoid main() {    var age = 10;    if(age == 10){       print("10 is perfect");    } }Since in the above code the age == 10 evaluates ... Read More

Hierarchical inheritance is the case of inheritance when two classes inherit a single class.The syntactic representation of a hierarchical inheritance looks something like this −class A {} class B extends A {} class C extends A {}In the above syntactic representation, we can see that two classes, namely B and C are inheriting (or extending) class A.ExampleLet's consider an example of hierarchical inheritance in dart. Consider the example shown below − Live Democlass Parent{    void printName(){       print("Inside class Parent");    } } class Daughter extends Parent{    void age(age){       print("Her age is: ${age}"); ... Read More

A Hello World program is the first program that you learn whenever you are learning a new programming language. It might be a simple program but it is a great entry point as you get to know how a program works in Dart, how to run a dart file. It provides a way to test the systems and environment that you are using.An important prerequisite before running a Hello World in Dart is to have the Dart SDK installed on your local machine. You can install the Dart SDK from this link.Writing Hello World ProgramThe first thing that you need ... Read More

Reading and writing access to objects is very important in any programming language. Getter and Setter are the exact methods that we use when we want to access the reading and writing privileges to an object's properties.SyntaxA getter usually looks something like this -returnType get fieldName {    // return the value }The returnType is the type of data we are returning. The get keyword is what tells us and the compiler that is a getter, and then lastly we have the fieldName whose value we are trying to get.A setter usually looks something like this −set fieldName {    // set the ... Read More