Data Types - Part 2
Primitive Data Types: number, string, Boolean
Special Data Types: undefined, null
Composite Data Types: object etc.
Primitive Data Types: Value Types
1. number: indicates both integer and real numbers
Integers: means whole numbers
Ex: 122, 2000, -400, etc
Real numbers: means float numbers, i.e. numbers containing floating point
Ex: 3.142, 9.8,-48.32 etc.
2. string: indicates sequence of characters enclosed in double quotations or single quotations
i.e. Textual data.
If a string begins with single quote then it has to end with single quote and
If a string begins with double quote then it has to end with double quote.
3. boolean: indicates logical or conditional result
Boolean data type has two values true and false value.
Special Data Types: Default Values
1. undefined: indicates un-initialized.
It is the default value of un-initialized variable.
If we store undefined value in a variable its type will be set to undefined.
2. null: indicates the nothing.
If we store null in a variable its type is set to object.
Object type is also known as reference or pointer type,
A variable of type object points or refers to another memory location; if it should not point to any memory location then assign a value null.
Composite Data Types: Reference types or Object types
Instead of holding value they hold the address of another memory location.
Ex: Arrays, functions, RegExp, Date etc. are all example for Object types