geek1--Loops & Control Structure--B

Question 12 CORRECT

#include <stdio.h>   int main() {   int i;     for (i = 1; i != 10; i += 2)     printf(" GeeksQuiz ");   return 0; }

A	GeeksQuiz GeeksQuiz GeeksQuiz GeeksQuiz GeeksQuiz
	GeeksQuiz GeeksQuiz GeeksQuiz .... infinite times
C	GeeksQuiz GeeksQuiz GeeksQuiz GeeksQuiz
D	GeeksQuiz GeeksQuiz GeeksQuiz GeeksQuiz GeeksQuiz GeeksQuiz

Discuss it

Question 12 Explanation: 

The loop termination condition never becomes true and the loop prints GeeksQuiz infinite times. In general, if a for or while statement uses a loop counter, then it is safer to use a relational operator (such as <) to terminate the loop than using an inequality operator (operator !=).

Question 13 CORRECT

What will be the output of the following C program segment? (GATE CS 2012)

char inchar = 'A'; switch (inchar) { case 'A' :     printf ("choice A \n") ; case 'B' :     printf ("choice B ") ; case 'C' : case 'D' : case 'E' : default:     printf ("No Choice") ; }

A	No choice
B	Choice A
	Choice A Choice B No choice
D	Program gives no output as it is erroneous

Discuss it

Question 13 Explanation: 

There is no break statement in case ‘A’. If a case is executed and it doesn’t contain break, then all the subsequent cases are executed until a break statement is found. That is why everything inside the switch is printed. Try following program as an exercise.

int main()
{
    char inchar = 'A';
    switch (inchar)
    {
    case 'A' :
        printf ("choice A \n") ;
    case 'B' :
    {
        printf ("choice B") ;
        break;
    }
    case 'C' :
    case 'D' :
    case 'E' :
    default:
        printf ("No Choice") ;
    }
}

Question 14 CORRECT

Predict the output of the below program:

#include <stdio.h> int main() {     int i = 3;     switch(i)     {         printf("Outside ");         case 1: printf("Geeks");             break;         case 2: printf("Quiz");             break;         defau1t: printf("GeeksQuiz");     }     return 0; }

A	Outside GeeksQuiz
B	GeeksQuiz
	Nothing gets printed

Discuss it

Question 14 Explanation: 

In a switch block, the control directly flows within the case labels(or dafault label). So, statements which do not fall within these labels, Outside is not printed. Please take a closer look at the default label. Its defau1t, not default which s interpreted by the compiler as a label used for goto statements. Hence, nothing is printed in the above program.

Question 15 CORRECT

In the following program, X represents the Data Type of the variable check.

#include <stdio.h> int main() {     X check;     switch (check)     {         // Some case labels     }     return 0; }

Which of the following cannot represent X?

A	int
B	char
C	enum
	float

Discuss it

Question 15 Explanation: 

A switch expression can be int, char and enum. A float variable/expression cannot be used inside switch.

Question 16 ****CORRECT

What is the output of the following program?

#include <stdio.h> int main() {     char check = 'a';     switch (check)     {         case 'a' || 1: printf("Geeks ");                   case 'b' || 2: printf("Quiz ");                     break;         default: printf("GeeksQuiz");     }     return 0; }

A	Geeks
B	Geeks Quiz
C	Geeks Quiz GeeksQuiz
	Compile-time error

Discuss it

Question 16 Explanation: 

An expression gets evaluated in a case label. Both the cases used are evaluated to 1(true). So compile-time error: duplicate case value is flashed as duplicated cases are not allowed.

Question 17 ***********WRONG

Predict the output of the following program:

#include <stdio.h> int main() {     int check = 20, arr[] = {10, 20, 30};     switch (check)     {         case arr[0]: printf("Geeks ");         case arr[1]: printf("Quiz ");         case arr[2]: printf("GeeksQuiz");     }     return 0; }

A	Quiz
	Quiz GeeksQuiz
C	GeeksQuiz
	Compile-time error

Discuss it

Question 17 Explanation: 

The case labels must be constant inside switch block. Thats why the compile-time error: case label does not reduce to an integer constant is flashed.

Question 18 CORRECT

How many times GeeksQuiz is printed

#include<stdio.h> int main() {     int i = -5;     while (i <= 5)     {         if (i >= 0)             break;         else         {             i++;             continue;         }         printf("GeeksQuiz");     }     return 0; }

A	10 times
B	5 times
C	Infinite times
	0 times

Discuss it

Question 18 Explanation: 

The loop keeps incrementing i while it is smaller than 0. When i becomes 0, the loop breaks. So GeeksQuiz is not printed at all.

Question 19 CORRECT

#include <stdio.h> int main() {     int i = 3;     while (i--)     {         int i = 100;         i--;         printf("%d ", i);     }     return 0; }

A	Infinite Loop
	99 99 99
C	99 98 97
D	2 2 2

Discuss it

Question 19 Explanation: 

Note that the i–- in the statement while(i-–) changes the i of main() And i== just after declaration statement int i=100; changes local i of while loop.

Question 20 ****WRONG

#include <stdio.h> int main() {     int x = 3;     if (x == 2); x = 0;     if (x == 3) x++;     else x += 2;       printf("x = %d", x);       return 0; }

	x = 4
	x = 2
C	Compiler Error
D	x = 0

Discuss it

Question 20 Explanation: 

Value of x would be 2. Note the semicolon after first if statement. x becomes 0 after the first if statement. So control goes to else part of second if else statement.

Question 21 ***WRONG

#include<stdio.h> int main() {     int a = 5;     switch(a)     {     default:         a = 4;     case 6:         a--;     case 5:         a = a+1;     case 1:         a = a-1;     }     printf("%d \n", a);     return 0; }

	3
B	4
	5
D	None of these

Discuss it

note-- execution from default on ward starts only whwn there is no matching 

Question 21 Explanation: 

There is no break statement, so first a = a + 1 is executed, then a = a-1 is executed.

Question 22 CORRECT

Which combination of the integer variables x, y and z makes the variable a get the value 4 in the following expression?

a = ( x > y ) ? (( x > z ) ? x : z) : (( y > z ) ? y : z )

	x = 3, y = 4, z = 2
B	x = 6, y = 5, z = 3
C	x = 6, y = 3, z = 5
D	x = 5, y = 4, z = 5

Discuss it

Question 22 Explanation: 

The given expression assigns maximum among three elements (x, y and z) to a.

Question 23 WRONG

Consider the C program below.

#include <stdio.h> int *A, stkTop; int stkFunc (int opcode, int val) {     static int size=0, stkTop=0;     switch (opcode)     {     case -1:         size = val;         break;     case 0:         if (stkTop < size ) A[stkTop++]=val;         break;     default:         if (stkTop) return A[--stkTop];     }     return -1; } int main() {     int B[20];     A=B;     stkTop = -1;     stkFunc (-1, 10);     stkFunc (0, 5);     stkFunc (0, 10);     printf ("%d\n", stkFunc(1, 0)+ stkFunc(1, 0)); }

The value printed by the above program is ___________

A	9
	10
	15
D	17

Discuss it

Question 23 Explanation: 

The code in main, basically initializes a stack of size 10, then pushes 5, then pushes 10. Finally the printf statement prints sum of two pop operations which is 10 + 5 = 15.

    stkFunc (-1, 10);   // Initialize size as 10
    stkFunc (0, 5);    // push 5
    stkFunc (0, 10);   // push 10

    // print sum of two pop
    printf ("%d\n", stkFunc(1, 0) + stkFunc(1, 0));

You have completed 23/23 questions .
Your score is 61%.