Best Practice For Variable, Constant And Keywords In C

    simply in the programming the alphabets, digits and special symbols when properly combined         form constants, variable and keywords.

    A Constant is an entity that doesn't change, whereas, a variable is an entity that may change. A          keyword is a word that carries special meaning.

     Keywords are the words whose meaning has already been explained to the C compiler.

                    

        Rule for Constructing Integer Constant:

👉in integer constant must have at least one digit.

👉it can be any zero, positive or negative.

👉the allowable range for integer constant is -2147483648 to +2147483647.

 Note: No commas and blanks are allowed and if no sign precedes, it is assumed to be positive.

 

       Rule for Constructing Real Constant:

👉A real constant must have at least one digits.
👉it must have a decimal point.
👉it could be either positive or negative.

        Note: No comma and blanks allow and Default sign is positive

    

        Rule for Constructing Character Constant:

👉A character constant is a single alphabet, a single digit or a single symbol enclosed within a single inverted comma.
👉Example: 'a'.

        Note: both inverted commas should point with the left.

    

Rule for Constructing Variable Names:

A variable name is any combination of alphabets, digits and underscores.
the first character in the variable name must be an alphabet or underscore.
no commas, no blanks or no special symbol other than underscore.

        Note: Some compilers allow variable name whose length could be up to 247 characters.

There are only 32 keywords available in C language.