A term used in computer programming. It refers to those variables local to specific functions that are automatically allocated on the stack during each invocation of the function.
Example:
void
swap(int *a, int *b)
{
int temp; /* Automatic Variable! */
temp = *b;
*b = *a;
*a = temp;
}
They're called automatic because upon each invocation
of a function, storage space for these variables is automatically allocated on the stack for them.
Note: The keyword "auto" exists for explicitly
declaring an automatic variable within a block. Such
as:
...
{
auto int temp;
...
}
But since a variable within a block is automatic by default (as oposed to extern or static), the
use of auto is redundant and obsolete.