This set of Compilers Multiple Choice Questions & Answers (MCQs) focuses on “Cross Compiler – 2”.
- If we compile the sam.c file with the command “gcc -o sam sam.c”, then the executable file will be
- a) a.out
- b) sam
- c) sam.out
- d) None of the mentioned
Answer
Answer: b
Explanation: This is how the GCC is designed to take names of executable files.
- What will be output of the following code?
#include<stdio.h>
int main()
{
printf(“%d\t”,sizeof(6.5));
printf(“%d\t”,sizeof(90000));
printf(“%d”,sizeof(‘A’));
return 0;
}
- a) 8 4 2
- b) 8 4 2
- c) 8 4 4
- d) 8 4 3
Answer
Answer: c
Explanation: GCC compilers (32 bit compilers) size of:
double is 8 byte
long int is 8 byte
Character constant is 2 byte.
- What will be output of the following c code? ( according to GCC compiler)
#include<stdio.h>
int main()
{
signed x;
unsigned y;
x = 10 +- 10u + 10u +- 10;
y = x;
if(x==y)
printf(“%d %d”,x,y);
else if(x!=y)
printf(“%u %u”,x,y);
return 0;
}
- a) 0 0
- b) 65536 -10
- c) 0 65536
- d) Compilation error
Answer
Answer: a
Explanation: Consider on the expression:
x = 10 +- 10u + 10u +- 10;
10: It is signed integer constant.
10u: It is unsigned integer constant.
X: It is signed integer variable.
As we know operators enjoy higher precedence than binary operators. So
x = 10 + (-10u) + 10u + (-10);
= 10 + -10 + 10 + (-10);
= 0
So, Corresponding signed value of unsigned 10u is +10.
- What will be output of the following c code?
#include<stdio.h>
int main()
{
const int *p;
int a=10;
p=&a;
printf(“%d”,*p);
return 0;
}
- a) 0
- b) 10
- c) Garbage Value
- d) Any Memory address
Answer
Answer: b
Explanation: In the following declaration
const int *p;
p can keep address of constant integer.
- What will be output of the following c code?
#include<stdio.h>
int main()
{
int a= sizeof(signed) +sizeof(unsigned);
int b=sizeof(const)+sizeof(volatile);
printf(“%d”,a+++b);
return 0;
}
- a) 10
- b) 9
- c) 8
- d) Error
Answer
Answer: c
Explanation: Default data type of signed, unsigned, const and volatile is intSo, a = 4 and b =4
Now, a+++b
= a++ + b
= 4 + 4 //due to post increment operator.
=8
But in Linux gcc compiler size of int is 4 byte so your out will be 16.
- Which of the following is integral data type?
- a) void
- b) char
- c) float
- d) double
Answer
Answer: b
Expanation:
In c char is integral data type. It stores the ASCII value .
- What will be output of the following c code?
#include<stdio.h>
int main()
{
volatile int a=11;
printf(“%d”,a);
return 0;
}
- a) 11
- b) Garbage
- c) -2
- d) Cannot Predict
Answer
Answer: d
Explanation: Value of volatile variable can’t be predicted because its value can be changed by any microprocessor interrupt.
- What will be output of the following c code?
#include<stdio.h>
const enum Alpha
{
X,
Y=5,
Z
}p=10;
int main()
{
enum Alpha a,b;
a= X;
b= Z;
printf(“%d”,a+b-p);
return 0;
}
- a) -4
- b) -5
- c) 10
- d) 11
Answer
Answer: a
Explanation: Default value X is zero and
Z = Y + 1 = 5 + 1 = 6
So, a + b – p
=0 + 6 -10 = -4.
