This is a ppt of dart programming language that by technoship cell Government engineering college Idukki Kerala India

3. Dart language
By TechnoShip Cell Geci

4. Dart Programming Language
● Open-Source General-Purpose programming language.
● Developed by Google.
● This meant for the server as well as the browser.
● an object-oriented language.
● C-style syntax.

5. Designed By
Lars Bak and Kasper Lund

6. Why Dart?
Help app developers
write complex, high
fidelity client apps for
the modern web.

7. Dart v/s javaScript

8. Where Dart Using?
● Flutter Created on top of Dart.
● Flutter has an Power Full Engine to
perform smooth and lag less
performance.
● Flutter used for:

9. Going deep into

10. First Dart Program
// Entry point to Dart program
main() {
print('Hello from Dart');
}
• main() - The special, required, top-level function where app execution starts.
• Every app must have a top-level main() function, which serves as the entry
point to the app.

11. Comments In Dart
• Dart supports both single line and multi line comments
// Single line comment
/* This is
an example
of multi line
comment */

12. Built in Types
• number
• int - Integer (range -253 to 253)
• double - 64-bit (double-precision)
• string
• boolean – true and false
• symbol
• Collections
• list (arrays)
• map
• set
• runes (for expressing Unicode characters in a string)

13. Variable Initializing
● var name=”technoship”;
● var reg=123;
var keyword used to create static variables.
● dynamic name=”technoship”;
● dynamic reg=123;
dynamic keyword used to create dynamic variables.
● String name=”technoship”;
● int reg=123;
Variables can initialize using its data type.

14. List and Map
● List
List names=<String>[“Arun”,”Alen”];
List is used to store same data type items
● Map
Map rollno_name=<int,String>{1:”Arun”,2:”Alen”};
Map is an object that associates keys and values

15. String Interpolation
● Identifiers could be added within a string literal using $identifier or
$varaiable_name syntax.
var user = 'Bill';
var city = 'Bangalore';
print("Hello $user. Are you from $city?");
// prints Hello Bill. Are you from Bangalore?
● You can put the value of an expression inside a string by using ${expression}
print('3 + 5 = ${3 + 5}'); // prints 3 + 5 = 8

16. Operators in

17. Operands and operator
● An expression is a special kind of statement that evaluates to a value.
● Every expression is composed of −
○ Operands − Represents the data
○ Operator − Defines how the operands will be processed to produce a
value.
● Consider the following expression – "2 + 3". In this expression, 2 and 3 are
operands and the symbol "+" (plus) is the operator.

18. operators that are available in Dart.
● Arithmetic Operators
● Equality and Relational Operators
● Type test Operators
● Bitwise Operators
● Assignment Operators
● Logical Operators

19. Arithmetic Operators

20. Arithmetic Operators(cont..)

21. Equality and Relational Operators

22. Type test Operators

23. Bitwise Operators

24. Assignment Operators

25. Assignment Operators(cont..)

26. Logical Operators

27. Control flow statements
● if and else
● for loops (for and for in)
● while and do while loops
● break and continue
● switch and case

28. if and else
● if and else
var age = 17;
if(age >= 18){
print('you can vote');
}
else{
print('you can not vote');
}
● curly braces { } could be omitted when the blocks have a single line of code

29. Conditional Expressions
● Dart has two operators that let you evaluate expressions that might otherwise
require ifelse statements −
○ condition ? expr1 : expr2
● If condition is true, then the expression evaluates expr1 (and returns its value);
otherwise, it evaluates and returns the value of expr2.
● Eg:
○ var res = 10 > 12 ? "greater than 10":"lesser than or equal to 10";
● expr1 ?? expr2
● If expr1 is non-null, returns its value; otherwise, evaluates and returns the
value of expr2

30. else if
● Supports else if as expected
var income = 75;
if (income <= 50){
print('tax rate is 10%');
}
else if(income >50 && income <80){
print('tax rate is 20%');
}
else{
print('tax rate is 30%');
}

31. While & do..while
● While in dart
var num=0;
while(num<5){
print(num);
i=i+1;
}
● do..while in dart
var num=0;
do{
print(num);
i=i+1;
}while(num<5);

32. for loops
● Supports standard for loop (as
supported by other languages
that follow C like syntax)
for(int ctr=0; ctr<5; ctr++){
print(ctr);
}
● Iterable classes such as List and
Set also support the for-in form of
iteration
var cities=['Kolkata','Bangalore'];
for(var city in cities){
print(city);
}

33. switch case
● Switch statements compare integer, string, or compile-time constants
● Enumerated types work well in switch statements
● Supports empty case clauses, allowing a form of fall-through
var window_state = 'Closing';
switch(window_state){
case 'Opening' : print('Window is opening');
Break;
case 'Closing' : print('Window is Closing');
break;
default:print(“Non of the options”);

34. Functions in

35. Implementing a function
● Syntax
Return_type function function_name(parameters_list){
Function body;
}
● Eg:
Bool isOne(int a){
if(a==0){
return 0;
}
return 1;
}

36. Lambda function
● Syntax
[return_type]function_name(parameters)=>expression;
● Eg:
printMsg()=>print("hello");
int test()=>1234;

37. Parameters types
● Named Parameters
● Optional Parameters
● Default Parameters

38. Named Parameters
● eg:
Function definition :
void enableFlags({bool bold, bool hidden}) {...}
Function call:
enableFlags(bold: true, hidden: false);

39. Optional Parameters
● Wrapping a set of function parameters in [ ] marks them as optional positional
parameters:
● Eg:
Function definition :
void enableFlags(bool bold, [bool hidden]) {...}

40. Default Parameters
● Your function can use = to define default values for both named and
positional parameters.
● The default values must be compile-time constants.
● default value is provided, the default value is null.
● Eg:
void enableFlags({bool bold = false, bool hidden = false}) {...}

41. Exceptions in

42. Exception
● Exceptions are errors indicating that something unexpected happened.
● When an Exception occurs the normal flow of the program is disrupted and
the program/Application terminates abnormally.
● Eg
var n=10~/0;
Output:
Error occured ZeroDivision.

43. The try / on / catch Blocks
● syntax
try {
// code that might throw an exception
}
on Exception1 {
// code for handling exception
}
catch Exception2 {
// code for handling exception
}finally {
// code that should always execute; irrespective of the exception
}

44. Example try / on / catch
● try {
res = 10 ~/ 0;
}
on IntegerDivisionByZeroException
{
print('Cannot divide by zero');
}
● try {
res = 10 ~/ 0;
}
catch(e) {
print(e);
}

45. Exceptions in dart

46. Throw
● The throw keyword is used to explicitly raise an exception.
● A raised exception should be handled to prevent the program from exiting
abruptly.
● The syntax for raising an exception explicitly is −
throw new Exception_name();

47. Eg : of Throws
main() {
try {
test_age(-2);
}
catch(e) {
print('Age cannot be negative');
}
}
void test_age(int age) {
if(age<0) {
throw new FormatException();
}
}

48. object oriented programming
concepts(oop)

49. OOPs (Object-Oriented Programming System)
● Object means a real-world entity such as a pen, chair, table, computer, watch,
etc.
● Object-Oriented Programming is a methodology or paradigm to design a
program using classes and objects.
● It simplifies software development and maintenance by providing some
concepts:-
○ Object
○ Class
○ Inheritance
○ Polymorphism
○ Abstraction
○ Encapsulation

51. Object
● Any entity that has state and behavior is known as an object. For example, a
chair, pen, table, keyboard, bike, etc. It can be physical or logical.
● An Object can be defined as an instance of a class.
● An object contains an address and takes up some space in memory.
● Objects can communicate without knowing the details of each other's data or
code.
● Example: A dog is an object because it has states like color, name, breed, etc.
as well as behaviors like wagging the tail, barking, eating, etc.

52. Class
● Collection of objects is called class. It is a logical entity.
● A class can also be defined as a blueprint from which you can create an
individual object. Class doesn't consume any space.

53. Inheritance
● When one object acquires all the properties and behaviors of a parent object,
it is known as inheritance.
● It provides code reusability.
● It is used to achieve runtime polymorphism.
● Types of inheritance:-
○ Single Inheritance
○ Multiple Inheritance
○ Hierarchical Inheritance
○ Multilevel Inheritance
○ Hybrid Inheritance (also known as Virtual Inheritance)

55. Polymorphism
● If one task is performed in different ways, it is known as polymorphism.
● For example: to convince the customer differently, to draw something, for
example, shape, triangle, rectangle, etc.
● Another example can be to speak something; for example, a cat speaks
meow, dog barks woof, etc.

56. Abstraction
● Hiding internal details and showing functionality is known as abstraction.
● For example phone call, we don't know the internal processing.

57. Encapsulation
● Binding (or wrapping) code and data together into a single unit are known as
encapsulation.
● For example, a capsule, it is wrapped with different medicines.

58. OOP in

59. Declaring a Class in dart
● Use the class keyword to declare a class in Dart.
● A class definition starts with the keyword class followed by the class name;
● The class body enclosed by a pair of curly braces.
● Syntax
class class_name {
<fields>
<getters/setters>
<constructors>
<functions>
}

60. A class definition can include the following −
● Fields − A field is any variable declared in a class. Fields represent data
pertaining to objects.
● Setters and Getters − Allows the program to initialize and retrieve the values
of the fields of a class. A default getter/ setter is associated with every class.
However, the default ones can be overridden by explicitly defining a setter/
getter.
●

61. Thank You..
PPT created by Vishnu Suresh