Initializers
An initializer is an optional part of a data declaration that specifies an initial value of a data object. The initializers that are legal for a particular declaration depend on the type and storage class of the object to be initialized.
The initializer consists of the = symbol followed
by an initial expression or a brace-enclosed list of initial
expressions separated by commas. Individual expressions must be separated
by commas, and groups of expressions can be enclosed in braces and
separated by commas. Braces ({ }) are optional if
the initializer for a character string is a string literal. The number
of initializers must not be greater than the number of elements to
be initialized. The initial expression evaluates to the first value
of the data object.
= expression. For example, the
following data definition uses the initializer = 3 to
set the initial value of group to 3:
int group = 3;
You
can initialize variables at namespace scope with nonconstant expressions.
You
cannnot initialize variables at global scope with nonconstant expressions.
Initialization and storage classes discusses the rules for initialization according to the storage class of variables.
Designated initializers for aggregate types (C only) describes designated initializers, which are a C99 feature that can be used to initialize arrays, structures, and unions.