1. The document discusses key concepts in TypeScript including variables, types, operators, functions, classes, and inheritance. 2. It provides examples of how to declare variables, define types like number, string, boolean, array, and any, and use operators in TypeScript. 3. It also demonstrates how to create functions with optional and default parameters, define classes with inheritance and access modifiers, and discusses concepts like abstraction, encapsulation, modularity, and polymorphism in object oriented programming.

1. Neal Creative | click & Learn more
Neal Creative ©
TIP │ Use the built-in color
palette with green and yellow
for callouts and accents

2. 2
TypeScript
@Nikhil_Thomas

3. Javascript
Typescript

4. 4
Javascript

5. Abstraction is a
process where
you show only
“relevant” data
and “hide”
unnecessary
details from the
user
Encapsulation is
the process of
combining data
and functions
into a single unit
Modularity is
the act of
partitioning a
program into
single units
Polymorphism
is the ability of a
message or data
to be processed
in more than one
form
Inheritance is the
capability of one
class to inherit
properties from
another class
Basic Characteristics of Object Oriented Programming
1 2 3 4 5

6. 6
JavaScript Objects
OBJECT
Property 1 Property 2
Property 3 Property 4
Property 5 Property 6

7. 7
TYPESCRIPT:THE FUTURE
JAVASCRIPTTECHNOLOGIES KEEPS
CHANGES
LEARN USE
CREATE
MOVE WITH TECHNOLOGY

8. 1

9. 2 VARIABLES
TYPES
OPERATORS
FUNCTIONS
INTERFACE
CLASSES

10. VARIABLES
• Variables is a container to hold data and is done by var
keyword or let keyword.
• If we skip keyword to declare a variable we get an error
message as “cannot find name”.
Example:

11. Let vs Var Keyword
• The scope of a variable defined with var is global scope or
declared outside any function.
• The scope of a variable defined with let is block scope.
Example:-

12. 12
TYPES
• Type is a classification of data which tells the compiler or
interpreter how the programmer intends to use the
data(example : number, string).
• TypeScript is a strongly typed language and JavaScript is
a weakly typed language.
• TypeScript has a small number of build-in types,
including,
1. Number
2. String
3. Boolean
4. Array
5. Enum
6. Void & Any

13. Number & String Types
• The number type can be any set of any numbers
• The string type can be any string-i.e,any sequence of
Unicode characters encloses within a single or double
quotes

14. • You can also use template strings, which can span multiple
lines and have embedded expressions. These strings are
surrounded by the backtick/backquote (`) character, and
embedded expressions are of the form ${ expr }.

15. Boolean Types
• Booleans have only two valid value true/false
• Before version 0.9 of typeScript, the Boolean type was
described using bool keyword. There was a breaking
change in the 0.9 TypeScript language specifications,
which changed the keyword to boolean

16. Enum
• Enums allow us to define a set of named numeric constants.
• An enum can be defined using the enum keyword

17. Array Types
• Array types define both that a variable is an array and the
kind of elements it contain.
• Syntax:-
1. var [identifier]:type=[];
2. var [identifier]:Array<type>=[];
• Example:-

18. Any& Void types
• The any data type is the super type of all types in
TypeScript. It denotes a dynamic type.if we don’t know a
particular type we can choose any type
• void is a little like the opposite of any: the absence of
having any type at all. You may commonly see this as the
return type of functions that do not return a value

19. 19
Operators
• Operators are user for some operations on data.
• All the standard JavaScript operators are available in
TypeScript and they are,
1. Increment and Decrement Operator (“++“, “--“)
2. Binary Operator (“+“, “-“, “/“, “*“, “%“)
3. Bitwise Operator("~" , "&”, "|", "^" ,"<<" ,">>“)
4. Comparison Operators (“==" , “!=“ , “>", “<" ,"<=“, ”>=”)
5. Logical Operator (“&&“, “||“, ”!”)
6. Conditional Operator(“?:“)

20. 20
Functions
• Function is a block of code designed to perform a
particular task.
• Similar to JavaScript function.
• Several optional features:types,optional
parameters,default parameters.
• A parameter is a variable in a method definition. When a
method is called, the arguments are the data you pass
into the method's parameters.
Example:-

21. 21
Optional Parameters
• Parameters are required by default in TypeScript and we
are creating an optional parameters with a question
mark(?).
• Example:-

22. 22
Default Parameters
• In Default parameters we are simply assigning some text
as default value.when ever we omitted the argument
default value is taken.
Example:-

23. 23
Class
• Class is a way to bind data's and functions relating to any
entity together.
• Classes are defined with the class keyword and instantiated
with the new keyword.
• The syntax should look familiar if you’ve used C# or Java
before.

24. 24
Inheritance
• Classes can inherit properties from other classes
• A class inherits from another class using the extends
keyword.
• Child class inherits all methods and properties
Example:-

25. 25
Access Modifiers
• Typescript supports the common access modifiers that
control class members access.
• Typescript access modifiers are :
1. public : available on instances everywhere
2. private : not available for access outside the class.
3. protected : available on child classes but not on
instances directly.