4 Declarations

Declarations are used to introduce the identifiers used in a program and to specify their important attributes, such as type, storage class, and identifier name. A declaration that also causes storage to be reserved for an object or that includes the body of a function, is called a definition.

Section 4.1 covers general declaration syntax rules, Section 4.2 discusses initialization, and Section 4.3 describes external declarations.

The following kinds of identifiers can be declared. See the associated section for information on specific declaration and initialization syntax. Functions are discussed in Chapter 5.

• Simple objects (Section 4.4)

• Enumeration constants (Section 4.5)

• Pointers (Section 4.6)

• Arrays (Section 4.7)

• Structure and union members (Section 4.8)

• Tags (Section 4.9)

Note

Preprocessor macros created with the #define directive are not declarations. Chapter 8 has information on creating macros with preprocessor directives.