SYMBOLIC CONSTANTS OR MACRO

SYMBOLIC CONSTANTS OR MACRO:

In this #define is a macro used for a constant value to be assigned in the program.
for example: pi its value is being fixed as 3.14 so
we can assign:

ex: #define pi 3.14
Rules for symbolic constants:
1.symbolic names have the same form as variable names.these are written in capitals to differ from ordinary variables.
2.No blank space between the pound sign '#' and the word define is permitted.
3.'#' must be the first character in the line.
4.A blank space is required between #define and symbolic name and between the symbolic name and the constant.
5.#define statements must not end with a semicolon.
6.after definition,the symbolic name should not be assigned any other value within the program by using an assignment statement.For ex: STRENGTH=200;is illegal.
7.symbolic names are NOT declared for data types .its data types depends on the type of constant.