Explain The Storage Class auto
The Storage Class auto : Variables declared within function bodies are automatic by default. Thus, automatic is the most common of the four storage classes. Declarations of variables within blocks are implicitly of storage class 'automatic'. The keyword 'auto' can be used to explicitly specify the storage class. An example is
auto int a,b,c;
auto float f;
Because the storage class is automatic by default, the keyword 'auto' is seldom used.
When a block is entered, the sytem allocates memory for the automatic variables. Within that block, these variables are defined and are considered 'local' to that block. When the block exited, the system releases the memory that was set aside for the automatic variables. Thus, the values of these variables are lost.