Examples of Variables

Example 1 : what will be output of the following C program?

#include<stdio.h>

int main()

{

int goto = 5;

printf("%d",goto);

return 0;

}

Output:  Compilation error

Explanation:  Invalid variable name 'goto' is keyword in C. Variable name cannot be any of keywords of C language.

Example 2 : What will be output of the following C program?

#include<stdio.h>

int main()

{

int _ = 5;

int __= 10;

int ___;

___ = _ + __;

printf("%d",___);

return 0;

}

Output :  15

Explanation: Variable name can have only underscore.

Example 3 : What will be output of the following C program?

#include<stdio.h>

int main()

{

int abcdefghijklmnopqrstuvwxyz123456789 = 10;

int abcdefghijklmnopqrstuvwxyz123456 = 40;

printf("%d",abcdefghijklmnopqrstuvwxyz123456);

return 0;

}

Output : Compilation error 

Explanation: Only first 32 characters are significant in variable name. So compiler will show error : Multiple declaration of identifier abcdefghijklmnopqrstuvwxyz123456.

Example 4 : What will be output of the following C Program?

#include<stdio.h>

int main()

{

int xyz = 20;

int xyz;

printf("%d",xyz);

return 0;

}

Output : Compilation error.

Explanation : Two local variables cannot have same name in same scope.

Example 5 : What will be output of the following C Program?

#include<stdio.h>

int main()

{

int main = 50;

printf("%d", main);

return 0;

}

Output :  50

Explanation : Variable name can be ' main ' because it is not a keyword.