Automatic storage class or variables
Automatic variables are allocated space in the variable on the stack. To declare a variable automatic storage class auto specified.
eg: auto int n;
When you declare a variable, if the omitted variable storage class is automatic.
eg: int n;
When you declare an automatic variable initialization to be made explicit initial value is undefined.
The scope of an automatic variable is only for the
block, or any block within the block, in which it appears. All variables
declared within a function are auto by default. A variable can be defined as
automatic by placing the keyword auto at the beginning of the variable
Example: auto int a;
Take a look at the following example: