100 Multiple choice questions in C

void func(void){
printf("func");
((char*) 0)=0;

}
The function func(), triggers memory fault. Which one explains why "func" may NOT be printed before the crash?
Choice 1
Insufficient information to determine why the output fails.

Choice 2
printf() expects more than one argument. As only one argument is given, crash may actually occur inside printf().

Choice 3
Output stream is buffered and may not be flushed before the crash occurs. (Ans--?)

Choice 4
printf() always buffers output until a newline character appears in buffer. Since no newline was present in the format string, nothing is printed.

 

How does variable definition differ from variable declaration?

Choice 1
Definition allocates storage for a variable, but declaration only informs the compiler as to the variable's type.

Choice 2
Declaration allocates storage for a variable, but definition only informs the compiler as to the variable's type.

Choice 3
Variables may be defined many times, but may be declared only once.(Ans --?)

Choice 4
Variable definition must precede variable declaration.

Choice 5
There is no difference in C between variable declaration and variable definition.

 

Which one of the following is a true statement about pointers?

Choice 1
Pointer arithmetic is permitted on pointers of any type.(Ans-- ??)

Choice 2
A pointer of type void * can be used to directly examine or modify an object of any type.

Choice 3
Standard C mandates a minimum of four levels of indirection accessible through a pointer.

Choice 4
A C program knows the types of its pointers and indirectly referenced data items at runtime.

Choice 5
Pointers may be used to simulate call-by-reference.

 

unsigned int p=0;
(p^p)||p++||++p||p++;

What is the value of the variable "p" after executing the above code?

Choice 1
1

Choice 2
2 (Ans--??)

Choice 3
3

Choice 4
The value is undefined because "p" is initialized to 0.

 

Which is functionally equivalent of arithmetic right shift of signed int p by 2 and is portable?

Choice 1
p / 4 (Ans---??)

Choice 2
p / 2

Choice 3
p >>> 2

Choice 4
p >> 2

Choice 5
p > 0 ? p >> 2 | 1 << sizeof(p) * 8 - 1 : p >> 2

 

char var1[10];
char var2[5]="Forum";
strcpy(var1,var2);
printf("%s,%s",var1,var2);
What is the output of the above code?

Choice 1
No output as it is array overflow error.

Choice 2
"Forum Forum"

Choice 3
Results undefined. Depending on platform, code may cause access violation.

Choice 4
Compilation error because string pointers can be initialized with a string literals only

 

I think this result should be printed if the second array was defined as: var2[6]

 

Also Please mail the answers to brajrajsingh@gmail.com

 

Re: 100 Multiple choice questions in C (New Question?)

char buf[50]="Hello World";
char *ptr=buf+5;

What's the right way to copy 15 bytes from the location pointed by "ptr" to the beginning of "buf"?
Choice 1
memmove( buf, ptr, 15 ); (ans)

Choice 2
Illegal memory access because it will read memory past the end of the string.

Choice 3
strncpy( buf, ptr, 15 );

Choice 4
Cannot be done because the source and destination overlap.

Choice 5
memcpy( buf, ptr, 15 );

 

Re: 100 Multiple choice questions in C (Ask New Questions?)

struct node {
int id;
int lengh;
struct node *next;
struct node *prev;
unsighed char data[1];
}

Considering struct node, an aggregate type defined above, which one of the following might explain the declaration of its peculiar member data?
Choice 1

There is no difference between character unsigned char data and array unsigned char data [1] since each allocates only a single byte. Identical operations can be performed on both quantities. The choice was one of preference.
Choice 2

The programmer is declaring a bit field called data, which consists of only a single bit. struct node probably represents some hardware device.
Choice 3

data is probably used in conjunction with length and malloc() to create objects of variable size. struct node is essentially a header for an object of indeterminate size.
Choice 4

The information provided by the definition of struct node is insufficient to formulate a guess about the purpose of the member data or its strange declaration. (Ans)
Choice 5

The programmer has made a typo. If the programmer had intended to allocate only a single byte, the data would have been declared as unsigned char data instead.