double Data Type in C: Usage and Examples

Double data type is also same as float data type which allows up-to 10 digits after decimal. The range for double datatype is from 1E–37 to 1E+37.

double Variable Declaration and Variable Initialization:

Variable Declaration : To declare a variable , you must specify the data type & give the variable a unique name.

double area ;

Variable Initialization : To initialize a variable you must assign it a valid value.

area = 334343.14 ;

float Variable Declaration and Variable Initialization in two steps:

double area;
area = 334343.14;

Program

// A Java program to demonstrate double data type
class CharDemo {
   public static void main(String args[])
     {
           double area;
           area = 323323.14;
           System.out.println(area);
     }
  }

Output

323323.14
Press any key to continue . . .

double Variable Declaration and Variable Initialization in one line:

double  area= 334343.14 ;

Program

// A Java program to demonstrate double data type
class CharDemo {
   public static void main(String args[])
     {
           double area = 323323.14;
           System.out.println(area);
     }
  }

Output

323323.14
Press any key to continue . . .

Difference between float and double

The size of float (single precision float data type) is 4 bytes. And the size of double (double precision float data type) is 8 bytes. Floating point variables has a precision of 6 digits whereas the precision of double is 14 digits.