What is the difference between static and extern storage class in C?

static means a variable will be globally known only in this file. extern means a global variable defined in another file will also be known in this file, and is also used for accessing functions defined in other files. A local variable defined in a function can also be declared as static .

What is static extern variable in C?

Static variables in C have the following two properties: They cannot be accessed from any other file. Thus, prefixes “ extern ” and “ static ” cannot be used in the same declaration. They maintain their value throughout the execution of the program independently of the scope in which they are defined.

What is extern static in C++?

storage type ‘extern’ means the variable declared in another file. storage type ‘static’ means the value of the variable is static with respect to the scope of the variable. When the program reenter the scope you can retrieve the value. The scope can a function or a file or a class.

What is the extern keyword in C?

The extern keyword in C and C++ extends the visibility of variables and functions across multiple source files. In the case of functions, the extern keyword is used implicitly. But with variables, you have to use the keyword explicitly.

What are different types of storage classes in C?

There are four different types of storage classes that we use in the C language:

• Automatic Storage Class.
• External Storage Class.
• Static Storage Class.
• Register Storage Class.

Can we use static with extern?

By default, functions and global variables are visible within all linked files. “extern” keyword allows for declaration sans definition. But, this would mean that global variables are visible from everywhere. So, “static” keyword lets us limit the visibility of things within the same file.

What is extern function in C?

“extern” keyword is used to extend the visibility of function or variable. By default the functions are visible throughout the program, there is no need to declare or define extern functions. It just increase the redundancy. Variables with “extern” keyword are only declared not defined.

Can we use static and extern together in C++?

No. Those are storage class modifiers and you can only use one of them per declaration. By stating it is external to this file but only scoped to this file you are declaring an impossible storage class. The compiler should give you some error regarding a declaration with more than one storage class.

What is the scope of static class specifier in C?

What is the scope of static class specifier? Explanation: Within block is the scope of static class specifier.

Why is extern used in C?

What is difference between static and volatile in C?

A static variable refers to a class variable that’s shared among all instances. volatile: Volatile variables are those which are read and written to main memory. They aren’t stored in local cache and are always fetched from main memory.

What is static in C?

A static function in C is a function that has a scope that is limited to its object file. This means that the static function is only visible in its object file. A function can be declared as static function by placing the static keyword before the function name.

Why do we use extern in C?

What is static structure in C?

The static keyword in C has several effects, depending on the context it’s applied to. when applied to a variable declared inside a function, the value of that variable will be preserved between function calls.