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Articles by Mukul Latiyan
Page 4 of 37
const keyword in Dart Programming
Dart provides us with two ways in which we can declare variables with fixed values. One of them is by declaring a variable with a const keyword, and the other is by declaring the variable with a final keyword.It should be noted that both of them does provide an assurance that once a value is assigned to the variable with them, it won't change, but indeed they are slightly different from one another.constA variable that is declared using the const keyword cannot be assigned any other value. Also, the variable is known as a compile-time constant, which in turn means that ...
Read MoreConstructors in Dart Programming
Constructors are methods that are used to initialize an object when it gets created. Constructors are mainly used to set the initial values for instance variables. The name of the constructor is the same as the name of the class.Constructors are similar to instance methods but they do not have a return type.All classes in Dart have their own default constructor, if you don't create any constructor for a class, the compiler will implicitly create a default constructor for every class by assigning the default values to the member variables.We can create a constructor in Dart something like this −class ...
Read Morefinal keyword in Dart Programming
The final keyword in Dart is used to create constants or objects that are immutable in nature. The only difference between the final and const keyword is that final is a runtime-constant, which in turn means that its value can be assigned at runtime instead of the compile-time that we had for the const keyword.ExampleConsider the example shown below −void main(){ final int xy = 10; print(xy); }Output10In the above example, we declared an int variable with a final keyword, which means that the value once assigned to it won't change.ExampleConsider the example shown below −void main(){ final ...
Read MoreGetter and Setter in Dart Programming
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 MoreHello World in Dart Programming
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 MoreImmutable annotation in Dart Programming
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 −import 'pacakge:meta/meta.dart'; @immutable class User { final String name; User(this.name); User.withPrint(this.name){ ...
Read MoreInheritance in Dart Programming
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 MoreIterator class in Dart Programming
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 MoreLexical Scoping in 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 −void 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 the ...
Read MoreMethod Overriding in Dart Programming
We know that we can access the methods that are present in the superclass from a subclass by making use of the super keyword or by simply creating objects of the subclass. Though, there may be different occasions when we want the subclass object to do things differently to the same method when invoked using subclass objects. We can achieve this by defining the same method again in the subclass with the same name, same arguments and same return type as in the same method that is present inside the superclass.Now, when we invoke that method, the method present in ...
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