FLOATING POINT CONSTANT

A floating point constant is a single real number.It includes integer portion, a decimal point, 
fractional point and a exponent.While representing a floating point constant, either the digits 
before the decimal point (the integer portion) or the digits after the decimal point (the fractional 
portion ) can be omitted but not both.The decimal point can be omitted if an exponent is 
included.An exponent is represented in powers of 10 in decimal system.

eg:

12.34 is a valid floating point (real) constant.It can be represented in exponent form as follows:

      1.234E1 -> 1.234*10^1 -> 12.34
      1234E2 -> 1234*10^(-2) -> 12.34
      0.1234e2 -> 0.1234*10^2 -> 12.34

 The letter E or e is used to represent the floating point constant in exponent form.