Sunday, 15 January 2012

Control Instructions


1.  How many times "IndiaBIX" is get printed?
#include<stdio.h>
int main()
{
    int x;
    for(x=-1; x<=10; x++)
    {
        if(x < 5)
            continue;
        else
            break;
        printf("IndiaBIX");
    }
    return 0;
}
A.
Infinite times
B.
11 times
C.
0 times
D.
10 times
Answer & Explanation
Answer: Option C


2.  How many times the while loop will get executed if a short int is 2 byte wide?
#include<stdio.h>
int main()
{
    int j=1;
    while(j <= 255)
    {
        printf("%c %d\n", j, j);
        j++;
    }
    return 0;
}
A.
Infinite times
B.
255 times
C.
256 times
D.
254 times
Answer & Explanation
Answer: Option B
Explanation:
The while(j <= 255) loop will get executed 255 times. The size short int(2 byte wide) does not affect the while() loop.


3.  Which of the following is not logical operator?
A.
&
B.
&&
C.
||
D.
!
Answer & Explanation
Answer: Option A
Explanation:
Bitwise operators:
& is a Bitwise AND operator.
Logical operators:
&& is a Logical AND operator.
|| is a Logical OR operator.
! is a NOT operator.
So, '&' is not a Logical operator.


4.  In mathematics and computer programming, which is the correct order of mathematical operators ?
A.
Addition, Subtraction, Multiplication, Division
B.
Division, Multiplication, Addition, Subtraction
C.
Multiplication, Addition, Division, Subtraction
D.
Addition, Division, Modulus, Subtraction
Answer: Option B
Explanation:
Simply called as BODMAS (Brackets, Order, Division, Multiplication, Addition and Subtraction).
Mnemonics are often used to help students remember the rules, but the rules taught by the use of acronyms can be misleading. In the United States the acronym PEMDAS is common. It stands for Parentheses, Exponents, Multiplication, Division, Addition, Subtraction. In other English speaking countries, Parentheses may be called Brackets, or symbols of inclusion and Exponentiation may be called either Indices, Powers or Orders, and since multiplication and division are of equal precedence, M and D are often interchanged, leading to such acronyms as BEDMAS, BIDMAS, BODMAS, BERDMAS, PERDMAS, and BPODMAS.


5.  Which of the following cannot be checked in a switch-case statement?
A.
Character
B.
Integer
C.
Float
D.
enum
Answer & Explanation
Answer: Option C
Explanation:
The switch/case statement in the c language is defined by the language specification to use an int value, so you can not use a float value.

switch( expression )
{
    case constant-expression1:    statements 1;
    case constant-expression2:    statements 2;   
    case constant-expression3:    statements3 ;
    ...
    ...
    default : statements 4;
}
The value of the 'expression' in a switch-case statement must be an integer, char, short, long. Float and double are not allowed.
6.  What will be the output of the program?
#include<stdio.h>
int main()
{
    int i=0;
    for(; i<=5; i++);
        printf("%d,", i);
    return 0;
}
A.
0, 1, 2, 3, 4, 5
B.
5
C.
1, 2, 3, 4
D.
6
Answer & Explanation
Answer: Option D
Explanation:
Step 1: int i = 0; here variable i is an integer type and initialized to '0'.
Step 2: for(; i<=5; i++); variable i=0 is already assigned in previous step. The semi-colon at the end of this for loop tells, "there is no more statement is inside the loop".

Loop 1: here i=0, the condition in for(; 0<=5; i++) loop satisfies and then i is incremented by '1'(one)
Loop 2: here i=1, the condition in for(; 1<=5; i++) loop satisfies and then i is incremented by '1'(one)
Loop 3: here i=2, the condition in for(; 2<=5; i++) loop satisfies and then i is incremented by '1'(one)
Loop 4: here i=3, the condition in for(; 3<=5; i++) loop satisfies and then i is increemented by '1'(one)
Loop 5: here i=4, the condition in for(; 4<=5; i++) loop satisfies and then i is incremented by '1'(one)
Loop 6: here i=5, the condition in for(; 5<=5; i++) loop satisfies and then i is incremented by '1'(one)
Loop 7: here i=6, the condition in for(; 6<=5; i++) loop fails and then i is not incremented.
Step 3: printf("%d,", i); here the value of i is 6. Hence the output is '6'.


7.  What will be the output of the program?
#include<stdio.h>
int main()
{
    char str[]="C-program";
    int a = 5;
    printf(a >10?"Ps\n":"%s\n", str);
    return 0;
}
A.
C-program
B.
Ps
C.
Error
D.
None of above
Answer & Explanation
Answer: Option A
Explanation:
Step 1: char str[]="C-program"; here variable str contains "C-program".
Step 2: int a = 5; here variable a contains "5".
Step 3: printf(a >10?"Ps\n":"%s\n", str); this statement can be written as

if(a > 10)
{
    printf("Ps\n");
}
else
{
    printf("%s\n", str);
}
Here we are checking a > 10 means 5 > 10. Hence this condition will be failed. So it prints variable str.
Hence the output is "C-program".


8.  What will be the output of the program?
#include<stdio.h>
int main()
{
    int a = 500, b = 100, c;
    if(!a >= 400)
        b = 300;
    c = 200;
    printf("b = %d c = %d\n", b, c);
    return 0;
}
A.
b = 300 c = 200
B.
b = 100 c = garbage
C.
b = 300 c = garbage
D.
b = 100 c = 200
Answer & Explanation
Answer: Option D
Explanation:
Initially variables a = 500, b = 100 and c is not assigned.
Step 1: if(!a >= 400)
Step 2: if(!500 >= 400)
Step 3: if(0 >= 400)
Step 4: if(FALSE) Hence the if condition is failed.
Step 5: So, variable c is assigned to a value '200'.
Step 6: printf("b = %d c = %d\n", b, c); It prints value of b and c.
Hence the output is "b = 100 c = 200"


9.  What will be the output of the program?
#include<stdio.h>
int main()
{
    unsigned int i = 65535; /* Assume 2 byte integer*/
    while(i++ != 0)
        printf("%d",++i);
    printf("\n");
    return 0;
}
A.
Infinite loop
B.
0 1 2 ... 65535
C.
0 1 2 ... 32767 - 32766 -32765 -1 0
D.
No output
Answer & Explanation
Answer: Option A
Explanation:
Here unsigned int size is 2 bytes. It varies from 0,1,2,3, ... to 65535.
Step 1:unsigned int i = 65535;
Step 2:
Loop 1: while(i++ != 0) this statement becomes while(65535 != 0). Hence the while(TRUE) condition is satisfied. Then the printf("%d", ++i); prints '1'(variable 'i' is already increemented by '1' in while statement and now increemented by '1' in printf statement) Loop 2: while(i++ != 0) this statement becomes while(1 != 0). Hence the while(TRUE) condition is satisfied. Then the printf("%d", ++i); prints '3'(variable 'i' is already increemented by '1' in while statement and now increemented by '1' in printf statement)
....
....
The while loop will never stops executing, because variable i will never become '0'(zero). Hence it is an 'Infinite loop'.


10.  What will be the output of the program?
#include<stdio.h>
int main()
{
    int x = 3;
    float y = 3.0;
    if(x == y)
        printf("x and y are equal");
    else
        printf("x and y are not equal");
    return 0;
}
A.
x and y are equal
B.
x and y are not equal
C.
Unpredictable
D.
No output
Answer & Explanation
Answer: Option A
Explanation:
Step 1: int x = 3; here variable x is an integer type and initialized to '3'.
Step 2: float y = 3.0; here variable y is an float type and initialized to '3.0'
Step 3: if(x == y) here we are comparing if(3 == 3.0) hence this condition is satisfied.
Hence it prints "x and y are equal".


11.  What will be the output of the program, if a short int is 2 bytes wide?
#include<stdio.h>
int main()
{
    short int i = 0;
    for(i<=5 && i>=-1; ++i; i>0)
        printf("%u,", i);
    return 0;
}
A.
1 ... 65535
B.
Expression syntax error
C.
No output
D.
0, 1, 2, 3, 4, 5
Answer & Explanation
Answer: Option E
Explanation:
for(i<=5 && i>=-1; ++i; i>0) so expression i<=5 && i>=-1 initializes for loop. expression ++i is the loop condition. expression i>0 is the increment expression.
In for( i <= 5 && i >= -1; ++i; i>0) expression i<=5 && i>=-1 evaluates to one.
Loop condition always get evaluated to true. Also at this point it increases i by one.
An increment_expression i>0 has no effect on value of i.so for loop get executed till the limit of integer (ie. 65535)


12.  What will be the output of the program?
#include<stdio.h>
int main()
{
    char ch;
    if(ch = printf(""))
        printf("It matters\n");
    else
        printf("It doesn't matters\n");
    return 0;
}
A.
It matters
B.
It doesn't matters
C.
matters
D.
No output
Answer & Explanation
Answer: Option D
Explanation:
printf() returns the number of charecters printed on the console.
Step 1: if(ch = printf("")) here printf() does not print anything, so it returns '0'(zero).
Step 2: if(ch = 0) here variable ch has the value '0'(zero).
Step 3: if(0) Hence the if condition is not satisfied. So it prints the else statements.
Hence the output is "It doesn't matters".
Note: Compiler shows a warning "possibly incorrect assinment".


13.  What will be the output of the program?
#include<stdio.h>
int main()
{
    unsigned int i = 65536; /* Assume 2 byte integer*/
    while(i != 0)
        printf("%d",++i);
    printf("\n");
    return 0;
}
A.
Infinite loop
B.
0 1 2 ... 65535
C.
0 1 2 ... 32767 - 32766 -32765 -1 0
D.
No output
Answer & Explanation
Answer: Option C
Explanation:
Here unsigned int size is 2 bytes. It varies from 0,1,2,3, ... to 65535.
Step 1:unsigned int i = 65536; here variable i becomes '0'(zero). because unsigned int varies from 0 to 65535.
Step 2: while(i != 0) this statement becomes while(0 != 0). Hence the while(FALSE) condition is not satisfied. So, the inside the statements of while loop will not get executed.
Hence there is no output.
Note: Don't forget that the size of int should be 2 bytes. If you run the above program in GCC it may run infinite loop, because in Linux platform the size of the integer is 4 bytes.


14.  What will be the output of the program?
#include<stdio.h>
int main()
{
    float a = 0.7;
    if(0.7 > a)
        printf("Hi\n");
    else
        printf("Hello\n");
    return 0;
}
A.
Hi
B.
Hello
C.
Hi Hello
D.
None of above
Answer & Explanation
Answer: Option D
Explanation:
if(0.7 > a) here a is a float variable and 0.7 is a double constant. The double constant 0.7 is greater than the float variable a. Hence the if condition is satisfied and it prints 'Hi'
Example:
#include<stdio.h>
int main()
{
    float a=0.7;
    printf("%.10f %.10f\n",0.7, a);
    return 0;
}
Output:
0.7000000000 0.6999999881


15.  What will be the output of the program?
#include<stdio.h>
int main()
{
    int a=0, b=1, c=3;
    *((a) ? &b : &a) = a ? b : c;
    printf("%d, %d, %d\n", a, b, c);
    return 0;
}
A.
0, 1, 3
B.
1, 2, 3
C.
3, 1, 3
D.
1, 3, 1
Answer & Explanation
Answer: Option A
Explanation:
Step 1: int a=0, b=1, c=3; here variable a, b, and c are declared as integer type and initialized to 0, 1, 3 respectively.
Step 2: *((a) ? &b : &a) = a ? b : c; The right side of the expression(a?b:c) becomes (0?1:3). Hence it return the value '3'.
The left side of the expression *((a) ? &b : &a) becomes *((0) ? &b : &a). Hence this contains the address of the variable a *(&a).
Step 3: *((a) ? &b : &a) = a ? b : c; Finally this statement becomes *(&a)=3. Hence the variable a has the value '3'.
Step 4: printf("%d, %d, %d\n", a, b, c); It prints "3, 1, 3".


16.  What will be the output of the program?
#include<stdio.h>
int main()
{
    int k, num = 30;
    k = (num < 10) ? 100 : 200;
    printf("%d\n", num);
    return 0;
}
A.
200
B.
30
C.
100
D.
500
Answer & Explanation
Answer: Option B


17.  What will be the output of the program?
#include<stdio.h>
int main()
{
    int a = 300, b, c;
    if(a >= 400)
        b = 300;
    c = 200;
    printf("%d, %d, %d\n", a, b, c);
    return 0;
}
A.
300, 300, 200
B.
Garbage, 300, 200
C.
300, Garbage, 200
D.
300, 300, Garbage
Answer & Explanation
Answer: Option C
Explanation:
Step 1: int a = 300, b, c; here variable a is initialized to '300', variable b and c are declared, but not initialized.
Step 2: if(a >= 400) means if(300 >= 400). Hence this condition will be failed.
Step 3: c = 200; here variable c is initialized to '200'.
Step 4: printf("%d, %d, %d\n", a, b, c); It prints "300, garbage value, 200". because variable b is not initialized.



18.  What will be the output of the program?
#include<stdio.h>
int main()
{
    int x=1, y=1;
    for(; y; printf("%d %d\n", x, y))
    {
        y = x++ <= 5;
    }
    printf("\n");
    return 0;
}
A.
2 1
3 1
4 1
5 1
6 1
7 0
B.
2 1
3 1
4 1
5 1
6 1
C.
2 1
3 1
4 1
5 1
D.
2 2
3 3
4 4
5 5
Answer & Explanation
Answer: Option A


19.  What will be the output of the program?
#include<stdio.h>
int main()
{
    int i = 5;
    while(i-- >= 0)
        printf("%d,", i);
    i = 5;
    printf("\n");
    while(i-- >= 0)
        printf("%i,", i);
    while(i-- >= 0)
        printf("%d,", i);
    return 0;
}
A.
4, 3, 2, 1, 0, -1
4, 3, 2, 1, 0, -1
B.
5, 4, 3, 2, 1, 0
5, 4, 3, 2, 1, 0
C.
Error
D.
5, 4, 3, 2, 1, 0
5, 4, 3, 2, 1, 0
5, 4, 3, 2, 1, 0
Answer & Explanation
Answer: Option A
Explanation:
Step 1: Initially the value of variable i is '5'.
Loop 1: while(i-- >= 0) here i = 5, this statement becomes while(5-- >= 0) Hence the while condition is satisfied and it prints '4'. (variable 'i' is decremented by '1'(one) in previous while condition)
Loop 2: while(i-- >= 0) here i = 4, this statement becomes while(4-- >= 0) Hence the while condition is satisfied and it prints '3'. (variable 'i' is decremented by '1'(one) in previous while condition)
Loop 3: while(i-- >= 0) here i = 3, this statement becomes while(3-- >= 0) Hence the while condition is satisfied and it prints '2'. (variable 'i' is decremented by '1'(one) in previous while condition)
Loop 4: while(i-- >= 0) here i = 2, this statement becomes while(2-- >= 0) Hence the while condition is satisfied and it prints '1'. (variable 'i' is decremented by '1'(one) in previous while condition)
Loop 5: while(i-- >= 0) here i = 1, this statement becomes while(1-- >= 0) Hence the while condition is satisfied and it prints '0'. (variable 'i' is decremented by '1'(one) in previous while condition)
Loop 6: while(i-- >= 0) here i = 0, this statement becomes while(0-- >= 0) Hence the while condition is satisfied and it prints '-1'. (variable 'i' is decremented by '1'(one) in previous while condition)
Loop 7: while(i-- >= 0) here i = -1, this statement becomes while(-1-- >= 0) Hence the while condition is not satisfied and loop exits.
The output of first while loop is 4,3,2,1,0,-1
Step 2: Then the value of variable i is initialized to '5' Then it prints a new line character(\n).
See the above Loop 1 to Loop 7 .
The output of second while loop is 4,3,2,1,0,-1
Step 3: The third while loop, while(i-- >= 0) here i = -1(because the variable 'i' is decremented to '-1' by previous while loop and it never initialized.). This statement becomes while(-1-- >= 0) Hence the while condition is not satisfied and loop exits.
Hence the output of the program is
4,3,2,1,0,-1
4,3,2,1,0,-1


20.  What will be the output of the program?
#include<stdio.h>
int main()
{
    int i=3;
    switch(i)
    {
        case 1:
            printf("Hello\n");
        case 2:
            printf("Hi\n");
        case 3:
            continue;
        default:
            printf("Bye\n");
    }
    return 0;
}
A.
Error: Misplaced continue
B.
Bye
C.
No output
D.
Hello Hi
Answer & Explanation
Answer: Option A
Explanation:
The keyword continue cannot be used in switch case. It must be used in for or while or do while loop. If there is any looping statement in switch case then we can use continue.


21.  What will be the output of the program?
#include<stdio.h>
int main()
{
    int x = 10, y = 20;
    if(!(!x) && x)
        printf("x = %d\n", x);
    else
        printf("y = %d\n", y);
    return 0;
}
A.
y =20
B.
x = 0
C.
x = 10
D.
x = 1
Answer & Explanation
Answer: Option C
Explanation:
The logical not operator takes expression and evaluates to true if the expression is false and evaluates to false if the expression is true. In other words it reverses the value of the expression.
Step 1: if(!(!x) && x)
Step 2: if(!(!10) && 10)
Step 3: if(!(0) && 10)
Step 3: if(1 && 10)
Step 4: if(TRUE) here the if condition is satisfied. Hence it prints x = 10.


22.  What will be the output of the program?
#include<stdio.h>
int main()
{
    int i=4;
    switch(i)
    {
        default:
           printf("This is default\n");
        case 1:
           printf("This is case 1\n");
           break;
        case 2:
           printf("This is case 2\n");
           break;
        case 3:
           printf("This is case 3\n");
    }
    return 0;
}
A.
This is default
This is case 1
B.
This is case 3
This is default
C.
This is case 1
This is case 3
D.
This is default
Answer & Explanation
Answer: Option B
Explanation:
In the very begining of switch-case statement default statement is encountered. So, it prints "This is default".
In default statement there is no break; statement is included. So it prints the case 1 statements. "This is case 1".
Then the break; statement is encountered. Hence the program exits from the switch-case block.


23.  What will be the output of the program?
#include<stdio.h>
int main()
{
    int i = 1;
    switch(i)
    {
        printf("Hello\n");
        case 1:
            printf("Hi\n");
            break;
        case 2:
            printf("\nBye\n");
            break;
    }
    return 0;
}
A.
Hello
Hi
B.
Hello
Bye
C.
Hi
D.
Bye
Answer & Explanation
Answer: Option B
Explanation:
switch(i) has the variable i it has the value '1'(one).
Then case 1: statements got executed. so, it prints "Hi". The break; statement make the program to be exited from switch-case statement.
switch-case do not execute any statements outside these blocks case and default
Hence the output is "Hi".


24.  What will be the output of the program?
#include<stdio.h>
int main()
{
    char j=1;
    while(j < 5)
    {
        printf("%d, ", j);
        j = j+1;
    }
    printf("\n");
    return 0;
}
A.
1 2 3 ... 127
B.
1 2 3 ... 255
C.
1 2 3 ... 127 128 0 1 2 3 ... infinite times
D.
1, 2, 3, 4

Answer: Option D


25.  What will be the output of the program?
#include<stdio.h>
int main()
{
    int x, y, z;
    x=y=z=1;
    z = ++x || ++y && ++z;
    printf("x=%d, y=%d, z=%d\n", x, y, z);
    return 0;
}
A.
x=2, y=1, z=1
B.
x=2, y=2, z=1
C.
x=2, y=2, z=2
D.
x=1, y=2, z=1
Answer & Explanation
Answer: Option A
Explanation:
Step 1: x=y=z=1; here the variables x ,y, z are initialized to value '1'.
Step 2: z = ++x || ++y && ++z; becomes z = ( (++x) || (++y && ++z) ). Here ++x becomes 2. So there is no need to check the other side because ||(Logical OR) condition is satisfied.(z = (2 || ++y && ++z)). There is no need to process ++y && ++z. Hence it returns '1'. So the value of variable z is '1'
Step 3: printf("x=%d, y=%d, z=%d\n", x, y, z); It prints "x=2, y=1, z=1". here x is increemented in previous step. y and z are not increemented.


26.  Point out the error, if any in the for loop.
#include<stdio.h>
int main()
{
    int i=1;
    for(;;)
    {
        printf("%d\n", i++);
        if(i>10)
           break;
    }
    return 0;
}
A.
There should be a condition in the for loop
B.
The two semicolons should be dropped
C.
The for loop should be replaced with while loop.
D.
No error
Answer & Explanation
Answer: Option D
Explanation:
Step 1: for(;;) this statement will genereate infinite loop.
Step 2: printf("%d\n", i++); this statement will print the value of variable i and increement i by 1(one).
Step 3: if(i>10) here, if the variable i value is greater than 10, then the for loop breaks.
Hence the output of the program is
1
2
3
4
5
6
7
8
9
10


27.  Point out the error, if any in the program.
#include<stdio.h>
int main()
{
    int a = 10;
    switch(a)
    {
    }
    printf("This is c program.");
    return 0;
}
A.
Error: No case statement specified
B.
Error: No default specified
C.
No Error
D.
Error: infinite loop occurs
Answer & Explanation
Answer: Option C
Explanation:
There can exists a switch statement, which has no case.


28.  Point out the error, if any in the program.
#include<stdio.h>
int main()
{
    int i = 1;
    switch(i)
    {
        printf("This is c program.");
        case 1:
            printf("Case1");
            break;
        case 2:
            printf("Case2");
            break;
    }
return 0;
}
A.
Error: No default specified
B.
Error: Invalid printf statement after switch statement
C.
No Error and prints "Case1"
D.
None of above
Answer & Explanation
Answer: Option C
Explanation:
switch(i) becomes switch(1), then the case 1: block is get executed. Hence it prints "Case1".
printf("This is c program."); is ignored by the compiler.
Hence there is no error and prints "Case1".


29.  Point out the error, if any in the while loop.
#include<stdio.h>
int main()
{
    int i=1;
    while()
    {
        printf("%d\n", i++);
        if(i>10)
           break;
    }
    return 0;
}
A.
There should be a condition in the while loop
B.
There should be at least a semicolon in the while
C.
The while loop should be replaced with for loop.
D.
No error
Answer & Explanation
Answer: Option A
Explanation:
The while() loop must have conditional expression or it shows "Expression syntax" error.
Example: while(i > 10){ ... }


30.  Which of the following errors would be reported by the compiler on compiling the program given below?
#include<stdio.h>
int main()
{
    int a = 5;
    switch(a)
    {
    case 1:
    printf("First");

    case 2:
    printf("Second");

    case 3 + 2:
    printf("Third");

    case 5:
    printf("Final");
    break;

    }
    return 0;
}
A.
There is no break statement in each case.
B.
Expression as in case 3 + 2 is not allowed.
C.
Duplicate case case 5:
D.
No error will be reported.
Answer & Explanation
Answer: Option C
Explanation:
Because, case 3 + 2: and case 5: have the same constant value 5.


31.  Point out the error, if any in the program.
#include<stdio.h>
int main()
{
    int P = 10;
    switch(P)
    {
       case 10:
       printf("Case 1");

       case 20:
       printf("Case 2");
       break;

       case P:
       printf("Case 2");
       break;
    }
    return 0;
}
A.
Error: No default value is specified
B.
Error: Constant expression required at line case P:
C.
Error: There is no break statement in each case.
D.
No error will be reported.
Answer & Explanation
Answer: Option B
Explanation:
The compiler will report the error "Constant expression required" in the line case P: . Because, variable names cannot be used with case statements.
The case statements will accept only constant expression.


32.  Point out the error, if any in the program.
#include<stdio.h>
int main()
{
    int i = 1;
    switch(i)
    {
        case 1:
           printf("Case1");
           break;
        case 1*2+4:
           printf("Case2");
           break;
    }
return 0;
}
A.
Error: in case 1*2+4 statement
B.
Error: No default specified
C.
Error: in switch statement
D.
No Error
Answer & Explanation
Answer: Option D
Explanation:
Constant expression are accepted in switch
It prints "Case1"


33.  Point out the error, if any in the while loop.
#include<stdio.h>
int main()
{
    void fun();
    int i = 1;
    while(i <= 5)
    {
        printf("%d\n", i);
        if(i>2)
            goto here;
    }
return 0;
}
void fun()
{
    here:
    printf("It works");
}
A.
No Error: prints "It works"
B.
Error: fun() cannot be accessed
C.
Error: goto cannot takeover control to other function
D.
No error
Answer & Explanation
Answer: Option C
Explanation:
A label is used as the target of a goto statement, and that label must be within the same function as the goto statement.
Syntax: goto <identifier> ;
Control is unconditionally transferred to the location of a local label specified by <identifier>.
Example:

#include <stdio.h>
int main()
{
    int i=1;
    while(i>0)
    {
        printf("%d", i++);
        if(i==5)
          goto mylabel;
    }
    mylabel:
    return 0;
}

Output: 1,2,3,4


34.  Point out the error, if any in the program.
#include<stdio.h>
int main()
{
    int a = 10, b;
    a >=5 ? b=100: b=200;
    printf("%d\n", b);
    return 0;
}
A.
100
B.
200
C.
Error: L value required for b
D.
Garbage value
Answer & Explanation
Answer: Option C
Explanation:
Variable b is not assigned.
It should be like:

b = a >= 5 ? 100 : 200;


35.  Which of the following statements are correct about the below program?
#include<stdio.h>
int main()
{
    int i = 10, j = 20;
    if(i = 5) && if(j = 10)
        printf("Have a nice day");
    return 0;
}
A.
Output: Have a nice day
B.
No output
C.
Error: Expression syntax
D.
Error: Undeclared identifier if
Answer & Explanation
Answer: Option C
Explanation:
"Expression syntax" error occur in this line if(i = 5) && if(j = 10).
It should be like if((i == 5) && (j == 10)).


36.  Which of the following statements are correct about the below program?
#include<stdio.h>
int main()
{
    int i = 10, j = 15;
    if(i % 2 = j % 3)
        printf("IndiaBIX\n");
    return 0;
}
A.
Error: Expression syntax
B.
Error: Lvalue required
C.
Error: Rvalue required
D.
The Code runs successfully
Answer & Explanation
Answer: Option B
Explanation:
if(i % 2 = j % 3) This statement generates "LValue required error". There is no variable on the left side of the expression to assign (j % 3).


37.  Which of the following statements are correct about the program?
#include<stdio.h>
int main()
{
    int x = 30, y = 40;
    if(x == y)
        printf("x is equal to y\n");

    else if(x > y)
        printf("x is greater than y\n");

    else if(x < y)
        printf("x is less than y\n")
    return 0;
}
A.
Error: Statement missing
B.
Error: Expression syntax
C.
Error: Lvalue required
D.
Error: Rvalue required
Answer & Explanation
Answer: Option A
Explanation:
This program will result in error "Statement missing ;"
printf("x is less than y\n") here ; should be added to the end of this statement.


38.  Which of the following statements are correct about an if-else statements in a C-program?
1:
Every if-else statement can be replaced by an equivalent statements using   ? ; operators
2:
Nested if-else statements are allowed.
3:
Multiple statements in an if block are allowed.
4:
Multiple statements in an else block are allowed.

A.
1 and 2
B.
2 and 3
C.
1, 2 and 4
D.
2, 3, 4
Answer & Explanation
Answer: Option D


39.  Which of the following statements are correct about the below program?
#include<stdio.h>
int main()
{
    int i = 0;
    i++;
    if(i <= 5)
    {
        printf("IndiaBIX\n");
        exit(0);
        main();
    }
    return 0;
}
A.
The program prints 'IndiaBIX' 5 times
B.
The program prints 'IndiaBIX' one time
C.
The call to main() after exit() doesn't materialize.
D.
The compiler reports an error since main() cannot call itself.
Answer & Explanation
Answer: Option B
Explanation:
Step 1: int i = 0; here variable i is declared as an integer type and initialized to '0'(zero).
Step 2: i++; here variable i is increemented by 1(one). Hence, i = 1
Step 3: if(i <= 5) becomes if(1 <= 5) here we are checking '1' is less than or equal to '5'. Hence the if condition is satisfied.
Step 4: printf("IndiaBIX\n"); It prints "IndiaBIX"
Step 5: exit(); terminates the program execution.
Hence the output is "IndiaBIX".


40.  Which of the following statements are correct about the below C-program?
#include<stdio.h>
int main()
{
    int x = 10, y = 100%90, i;
    for(i=1; i<10; i++)
    if(x != y);
        printf("x = %d y = %d\n", x, y);
    return 0;
}
1 :
The printf() function is called 10 times.
2 :
The program will produce the output x = 10 y = 10
3 :
The ; after the if(x!=y) will NOT produce an error.
4 :
The program will not produce output.

A.
1
B.
2, 3
C.
3, 4
D.
4
Answer & Explanation
Answer: Option B


41.  Which of the following sentences are correct about a for loop in a C program?
1:
for loop works faster than a while loop.
2:
All things that can be done using a for loop can also be done using a while loop.
3:
for(;;); implements an infinite loop.
4:
for loop can be used if we want statements in a loop get executed at least once.

A.
1
B.
1, 2
C.
2, 3
D.
2, 3, 4
Answer & Explanation
Answer: Option D


42.  Which of the following statements are correct about the below program?
#include<stdio.h>
int main()
{
    int n = 0, y = 1;
    y == 1 ? n=0 : n=1;
    if(n)
        printf("Yes\n");
    else
        printf("No\n");
    return 0;
}
A.
Error: Declaration terminated incorrectly
B.
Error: Syntax error
C.
Error: Lvalue required
D.
None of above
Answer & Explanation
Answer: Option C


43.  Which of the following sentences are correct about a switch loop in a C program?
1:
switch is useful when we wish to check the value of variable against a particular set of values.
2:
switch is useful when we wish to check whether a value falls in different ranges.
3:
Compiler implements a jump table for cases used in switch.
4:
It is not necessary to use a break in every switch statement.

A.
1,2
B.
1,3,4
C.
2,4
D.
2
Answer & Explanation
Answer: Option B


44.  A short integer is at least 16 bits wide and a long integer is at least 32 bits wide.
A.
True
B.
False
Answer & Explanation
Answer: Option A
Explanation:
The basic C compiler is 16 bit compiler, below are the size of it's data types
The size of short int is 2 bytes wide(16 bits).
The size of long int is 4 bytes wide(32 bits).


45.  If scanf() is used to store a value in a char variable then along with the value a carriage return(\r) also gets stored it.
A.
True
B.
False
Answer & Explanation
Answer: Option B
Explanation:
No, the carriage return tells the compiler to read the input from the buffer after ENTER key is pressed.


46.  The modulus operator cannot be used with a long double.
A.
True
B.
False
Answer & Explanation
Answer: Option A
Explanation:
fmod(x,y) - Calculates x modulo y, the remainder of x/y.
This function is the same as the modulus operator. But fmod() performs floating point or long double divisions.


47.  A char variable can store either an ASCII character or a Unicode character.
A.
True
B.
False
Answer & Explanation
Answer: Option A
Explanation:
Yes, we can store either an ASCII character or a Unicode character in a char variable.


48.  The way the break is used to take control out of switch and continue to take control of the beginning of the switch?
A.
Yes
B.
No
Answer & Explanation
Answer: Option B
Explanation:
continue can work only with loops and not with switch


49.  Can we use a switch statement to switch on strings?
A.
Yes
B.
No
Answer & Explanation
Answer: Option B
Explanation:
The cases in a switch must either have integer constants or constant expressions.


50.  We want to test whether a value lies in the range 2 to 4 or 5 to 7. Can we do this using a switch?
A.
Yes
B.
No
Answer & Explanation
Answer: Option A
Explanation:
We can do this in following switch statement

switch(a)
{
    case 2:
    case 3:
    case 4:
       /* some statements */
       break;
    case 5:
    case 6:
    case 7:
       /* some statements */
       break;
}


51.  By default, the data type of a constant without a decimal point is int, whereas the one with a decimal point is a double.
A.
Yes
B.
No
Answer & Explanation
Answer: Option A
Explanation:
6 is int constant.
6.68 is double.
6.68L is long double constant.
6.68f is float constant.

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