It is a placeholder in the memory that can be used to store the data,its value can be changed, using the data type we can specify that what kind of value will be stored in the variable.
It is divided into following two types:
a-value type/simple type/primitive type
b-reference type/complex type/non-primitive type
value-It is used to store the value and can be directly accessed i.e.
Major data types of value type:
a-Numeric i.e. 0-9 or decimal
b-String and Char i-e. 0-9, a-z, special char,but char can store only single char at a time while string can store many chars
c-Boolean-can store only true or false 0 or 1
Numeric-it will store only 0-9, it is furture divided as:
Integer-it will store only whole number
Short integer, long integer, very long integer
Float-it can store decimal as well as float, double
String and Char-it can store anything from a-z, 0-9 or special chars
Sting-can Store number of characters
Char-will store only single char
Boolean-it will accept only true or false or 0 or 1
Literals-A Literal is a type of value that is stored in a variable
Integer Literal -can store only whole number i.e.
Int age=25; //correct
Floating point literal-It can accept decimal i.e
Float age=25; //correct
String literal-It will accept anything but will be enclosed in the double quotes i.e.
string name = "Ram";//correct
string email = "firstname.lastname@example.org";//correct
string name = ram;//wrong
Character Literal-it will accept anything but only single char and will be enclosed in the single quotes i.e.
char gender = ‘M’;//correct
char gender = "Male";//incorrect
char gender = ram;//wrong
Boolean Literal- It will accept only true/false or 0/1 i.e.
boolean staus = true;//correct
boolean status = 0;// correct
boolean status = ram;//wrong
Identifier- it is name given to variable,constant,function,array
int = data type;// correct
salary = identifier;//wrong
It has the fixed value that cannot be changed during the program execution.We have to initialize the constant while declaring it.
To declare the constant const keyword is used i.e.
const int age=20;
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