ENUMERATED, typedef

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ENUMERATED DATA TYPES• An enumeration consists of a set of named integer constants. • An enumeration type declaration gives the name of the

(optional) enumeration tag and defines the set of named integer identifiers (called the "enumeration set," "enumerator constants," "enumerators," or "members"). A variable with enumeration type stores one of the values of the enumeration set defined by that type.

• Variables of enum type can be used in indexing expressions and as operands of all arithmetic and relational operators.

• Enumerations provide an alternative to the #define preprocessor directive with the advantages that the values can be generated for you and obey normal scoping rules.

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ENUMERATED DATA TYPES• enum identifier { enumerator-list }• Example• #include <stdio.h>• #include <conio.h>• #include <alloc.h>• void main()• {• clrscr();• enum month { jan = 1, feb, mar, apr, may, jun, jul, aug, sep,

oct, nov, dec };• printf("%d“,feb);• getch();• }

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typedef• A typedef declaration lets you define your own identifiers that

can be used in place of type specifiers such as int, float, and double.

• A typedef declaration does not reserve storage.• The names you define using typedef are not new data types,

but synonyms for the data types or combinations of data types they represent.

• The name space for a typedef name is the same as other identifiers.

• The exception to this rule is if the typedef name specifies a variably modified type. In this case, it has block scope.

• typedef int LENGTH;• LENGTH length, width, height;

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