Real constants are often called Floating Point constants.
It has three parts:
1. A sign (+ or -) preceding the number portion (optional).
2. A number portion (representing the base).
3. An exponent portion following the number portion (optional). This starts with E or E followed by an integer. The integer may be preceded by a sign.
A real constant must have at least one digit. It must have a decimal point. It could be either positive (default) or negative. No commas and blank are allowed within a real constant.
Some example of real constants:
: +.72
: +72
: +7.6E+2
: 24.4e-5
