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C Programming - Declarations and Initializations - Discussion

Discussion Forum : Declarations and Initializations - General Questions (Q.No. 10)
Declarations and Initializations
10.
In the following program where is the variable a getting defined and where it is getting declared? 
#include<stdio.h>
int main()
{
    extern int a;
    printf("%d\n", a);
    return 0;
}
int a=20;
extern int a is declaration, int a = 20 is the definition
int a = 20 is declaration, extern int a is the definition
int a = 20 is definition, a is not defined
a is declared, a is not defined
Answer: Option
Explanation:

- During declaration we tell the datatype of the Variable.

- During definition the value is initialized.

Discussion:
46 comments Page 2 of 5.
Pooja said:   1 decade ago
External variable is declared as:
extern <data_type> <var>;
It is present in another program and we are refering it.
So we have to define it outside the main().....
Ravi Karthick said:   1 decade ago
Extern means external declaration that is declared for outside the function,so that a that is declared as extern and defined in outside the main ar a=20
Laxmi said:   9 years ago
extern int a=2; it is a definition. Because variable a is initialized to 2 then memory is created for a. That's why we call it as a definition.
Mounika said:   10 years ago
Absolutely option A is correct answer.

But, declaration is outside of the main function.

So, could you please explain more about that?
Pawan Asati said:   1 decade ago
option A is correct because extern is a storage class so a is treated as global variable so it definition can be out of main we write.
Jyoti mishra said:   1 decade ago
What is the program for this output?

          *
        *   *
      *   *   *
    *   *    *   *
  *   *    *   *   *
Snehal kadam said:   2 decades ago
In main, "extern int a" is declaration is ok.
but it is defined in outside;
so ,is the option c is correct???
M.DHILIP BABU said:   1 decade ago
Why was declared int a=20 outside? suppose int a=20 declared inside of the function what is the o/p of this program?
Nandhi said:   1 decade ago
The variables are defined outside the main block, when that variable is declared as with the keyword 'extern'.
Anusha said:   10 years ago
If we give like this extern int a = 2;

Is it a declaration or definition?

Please can someone explain this?
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