External Variables Quiz Online Practice Test

1. What will this C code produce as output?
#include <stdio.h>
void main()
{
m();
printf("%d", x);
}
int x;
void m()
{
x = 4;
}

2. What will this C code output?
#include <stdio.h>
int x;
void main()
{
printf("%d", x);
}

3. What will this C code produce as output?
#include <stdio.h>
int x = 5;
void main()
{
int x = 3;
printf("%d", x);
{
x = 4;
}
printf("%d", x);
}

4. What will this C code output?
#include <stdio.h>
int x = 5;
void main()
{
int x = 3;
printf("%d", x);
{
int x = 4;
}
printf("%d", x);
}

5. Functions in C are always _________

6. Which variable is considered external in the following C code?
#include <stdio.h>
int func(int a)
{
int b;
return b;
}
int main()
{
int c;
func(c);
}
int d;

7. What will this C code output?
#include <stdio.h>
int main()
{
printf("%d", d++);
}
int d = 10;

8. What will this C code produce as output?
#include <stdio.h>
double var = 8;
int main()
{
int var = 5;
printf("%d", var);
}

9. What will this C code output?
#include <stdio.h>
double i;
int main()
{
printf("%g\n", i);
return 0;
}

10. In the following C code, where is the pointer `p` stored?
#include <stdio.h>
int *p = NULL;
int main()
{
int i = 0;
p = &i;
return 0;
}

11. In the following C code, where is the pointer `p` stored?
#include <stdio.h>
int *p;
int main()
{
int i = 0;
p = &i;
return 0;
}

12. Can the variable `i` be accessed by functions in another source file in the following C code?
#include <stdio.h>
int i;
int main()
{
printf("%d\n", i);
}

13. The property of an external variable being accessible by any source file is referred to by the C90 standard as __________.

14. What will be the output of the following C code?
#include <stdio.h>
int *i;
int main()
{
if (i == NULL)
printf("true\n");
return 0;
}

15. What will be the output of the following C code?
#include <stdio.h>
int *i;
int main()
{
if (i == 0)
printf("true\n");
return 0;
}

16. What will be the output of the following C code?
#include <stdio.h>
static int x = 5;
void main()
{
x = 9;
{
int x = 4;
}
printf("%d", x);
}