IDENTIFIERS IN C++

Constant

  §  Any information is constant.

  §  Data = information = constant.

Type of constant

In starting we focus on primary Constant

  §  Integer Constant

Integer constants are those constant which no point values.

For example; 23, -341, 0, 5

  §  Real Constants

Real constants are those constant which have point values.

For example; , 3.4, -0.06, 3.0

  §  Character Constants

Character constants are those constant which cover their values by single quote (‘).

For example; ‘a’, ‘A’, ‘+’, ‘2’, ‘ ’

Remember that:

Character constant having only and only following conditions;

  §  Cover by single quotes (‘).

  §  Having length 1 character only.

For example

-3 is not a character constant

Because -3 have two character – and 3.

Mobile number        à              integer constant
Mobile balance        à              Real Constant
your city name         à              string (not a character const.)

New Delhi                  à              Secondary constant (string)

  §  String Constants

String constants is the combination of character constant and shown by double quote (“).

For example; “Abhishek sharma”, “Delhi”.

Secondary Constant

  §  Secondary constants are dependent on primary constant.

For example

“Abhishek Sharma”   à combination of character const.

 

Memory Configuration

Variables

  § Variables are the name of the memory location where data will store.

  § Variable name is any combination of Alphabet (a to z or A to Z), digits (0 to 9) and Underscore (_).

  § Valid variable name can’t start with digits.

Keywords

  § Predefined word or Reserved words

  § Compiler already know the meaning of these words.

  § There are 48 keywords in C++

**You reached end of lecture**