Variables And Data Types In C++

Name	Size*	Range*	Example
Char	1 byte	Signed: -128 to 127 unsigned: 0 to 255	‘a’,’b’,’c’
Int	4 byte	Signed: -2147483648 to 2147483647 unsigned: 0 to 4294967295	123,456,73,1.
Bool	1byte	True or false	True,false
Float	4bytes	+/- 3.4e +/- 38 (~7 digits)	132.23,2.5,7
Double	8bytes	+/- 1.7e +/- 308 (~15 digits)	1647464364,567

Char
Char type of variable are use to assign or store a character which is enclose by 2 single quotes

char ch='k';   //ch contain 1 character  

Char b[]=”programming is fun.”; 

P

R

O

G

R

A

M

M

I

N

G

I

S

F

U

N

.

/0

In the sentence of “programming is fun.” Has 19 character include space. If we store this sentence in a char type array , we need to declare an array with 20 element.

Int
Int is use to define numeric variable holding whole number. The size of number that can be stored within -2,147,483,648 to 2,147,483,647 in 32 bit.

Bool
A Boolean constant is used to check the state of a variable, an expression, or a function, as true or false. To declare such a value, you use the bool keyword. The variable can then be initialized with the starting value. 

Float
Float is used to define numbers with fractional parts. It can represent the values of ranging from approximately 1.5 × 10−45 to 3.4 × 1038 with a precision of 7 digits

Double
A double is a larger float type that holds both bigger and more precise numbers.
Double variables are 8 bytes in size. The range of values is from 2.2250738585072020×10−308 to 1.7976931348623157×10308
More importantly, the precision of a double is 15 compared to 6 for a float. The precision of a number is how many digits (before and after the decimal point) it can store without errors occurring.