Storage classes in C

Brief description about Storage classes in C

According to the storage classes of “c” the lifetime of the auto variable is restricted within the body that’s why how many times we are calling the abc function that many times it will created. void xyz() { int a=5; --a; printf(“\na=%d”,a); } void main() { auto int a=10; ++a; xyz(); ++a; printf(“\na=%d”,a); } o/p : a=4; a=12;   void abc() { int a =10; --a; printf(“\na=%d”,a); }  

void main()

{ abc(); abc(); printf(“\n a=%d”,a); o/p : Error undefined symbol ‘a’  

• According to the storage classes of ‘c’ by default any type of variable storage class specifier is auto.
• The scope of the auto variable is restricted within the body that’s why abc() function related data, we can’t access in main() function

void main()

{ int a=10; clrscr(); auto int b=20; ++a; ++b; printf(“\n a=%d  b=%d”,a,b); }   o/p: Error declaration is not allowed here In ‘c’ programming language variable declaration must be exists top of the program before writing the first statement only.  

void main()

{ auto int a=5; int a=10; ++a; printf(“a=%d”,a); } o/p : Error multiple declaration for ‘a’   In any scope we construct a single variable by using anymore of unique name, if we are constructing multiple variable with the same name then it gives an error i.e, multiple declaration      

void main()

{ int a=5; ++a; printf(“\na=%d”,a); { auto int a=10; --a; printf(“\na=%d”,a); } o/p : a=6 a=9 a=7