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Chapterwise Question Bank CBSE Class 12 Computer Science (C++) – Pointers

Chapterwise Question Bank CBSE Class 12 Computer Science (C++) – Pointers

Exam Practice
Short Answer Type Questions [2/3 Mark]

Question 1:
Obtain the output from the following C++ program as expected to appear on the screen after its execution.    All India 2014,2013
Important Note
* All the desired header files are already included in the code, which are required to run the code.

void main()
{
char *Text = "AJANTA"; 
int *P, Num[] = {11,5,7,9};
P = Num;
cout<<*P<<Text<<endl;
Text++;
P++; 
cout<<*P<<Text<<endl;
}

Аnswer:
Output
1 AJANTA
5JANTA

Question 2:
Give the output of the following program segment: (Assuming all desired header file(s) are already included)    Delhi 2013C

void main()
{
float *Ptr,Points[]={20,50,30,40,10}; 
Ptr=Points; 
cout<<*Ptr<<endl;
Ptr+=2;
Points[2]+=2.5; 
cout<<*Ptr<<endl;
Ptr++;
(*Ptr)+=2.5; 
cout<<Points[3]<<endl;
}

Аnswer:
Output
20
32.5
42.5

Question 3:
Find the output of the following program: Delhi 2012

#include<iostream.h>
#include<ctype.h> 
typedef char Txt80[80];
void main()
{
char *PText;
Txt80 Txt = "Ur2GReAt"; 
int N = 6;
PText = Txt; 
whi1e(N >= 3)
{
Txt[N] = isupper(Txt[N])?
tolower(Txt[N]):toupper(Txt[N]); 
cout<<PText<<endl;
N--;
PText++;
}
}

Аnswer:
Output
Ur2GReat
r2GREat
2GrEat
grEat

Question 4:
Find the output of the following program: Delhi 2009C

#include<iostream.h> 
struct Score 
{
int Year; 
float topper;
};
void change(Score *s,int x=20)
{
s->topper = (s->topper+25)-x; 
s->Year++; 
}
void main()
{ 
Score Arr[] = {{2007, 100},{2008,95}}; 
Score *Point = Arr; 
change(Point,50);
cout<<Arr[0].Year<<"#"<<Arr[0].topper<<endl;
change(++Point);
cout<<Point->Year<<"#"<<Point->topper<<endl;
}

Аnswer:
Output
2008#75
2009# 100

Question 5:
Find the output of the following program:  All India 2011

#include<iostream.h> 
void main()
{
int Moves[] = {11, 22, 33, 44},*Queen; 
Queen = Moves;
Moves[2] += 22;
cout<<"Queen @"<<*Queen<<endl;
*Queen -= 11;
Queen += 2;
cout<<"[email protected]"<<*Queen<<endl;
Queen++;
cout<<"[email protected]"<<*Queen<<endl; 
cout<<"New [email protected]"<<*Moves[0]<<endl;
}

Аnswer:
There is an error in last line, i.e. *Moves[0], so the program will not run. In case, if there is no subscript in Moves pointer, then the output would be:
Queen @ 11
[email protected]
[email protected]
New [email protected]

Question 6:
Find the output of the following program: Delhi 2009

#include<iostream.h> 
void main()
{
int X[] = {10, 25, 30, 55, 110}; 
int *p = X; 
while(*p<110)
}
if(*p%3 != 0)
*p = *p+l; 
else
*p = *p+2;
P++;
}
for(int I=4;I>=1;I--)
{
cout<<X[I]<<"*"; 
if(I%3 == 0) 
cout<<endl;
}
cout<<X[0]*3<<endl;
}

Аnswer:
Output
110*56*
32*26*33

Question 7:
What will be the output?    All India 2008

#include<iostream.h>
#include<conio.h> 
void main()
{
static int a[]={0,1,2,3,4}; 
int *p[]={a,a+1,a+2,a+3,a+4}; 
int **ptr=p; 
ptr++;
cout<<ptr-p<<" "<<*ptr-a<<" "<<**ptr<<endl;
*ptr++;
cout<<ptr-p<<" "<<*ptr-a<<" "<<**ptr<<endl;
*++ptr;
cout<<ptr-p<<" "<<*ptr-a<<" "<<**ptr<<endl;
++*ptr;
cout<<ptr-p<<" "<<*ptr-a<<" "<<**ptr<<endl;
getch();
}

Аnswer:
Output
1 1 1
2 2 2
3 3 3
4 4 4

Question 8:
Find the output of the following program:

#include<iostream.h> 
void main()
{
int Numbers[] = {2,4,8,10}; 
int *ptr = Numbers; 
for(int c=0;c<3;c++)
{
cout<<*ptr<<"@"; 
ptr++;
}
cout<<endl; 
for(c=0;c<4;c++)
{
(*ptr)*= 2;
--ptr;
}
for(c=1;c<4;c++)
cout<<Numbers[c]<<"#"; 
cout<<endl;
}

Аnswer:
Output
[email protected]@[email protected]
8#16#20#

Question 9:
What will be the output of the following program?

#include<iostream.h>
#include<string.h> 
class state
{
char *state_name; 
int size; 
public: 
state()
{
size = 0;
state_name = new char[size+1];
}
state(char *s)
{
size = strlen(s); 
state_name = new char[size+1]; 
strcpy(state_name,s);
}
void display()
{
cout<<state_name<<endl;
}
void Replace(state &a,state &b)
{
size = a.size + b.size; 
delete state_name; 
state_name = new char[size+1]; 
strcpy(state_name,a.state_name); 
streat(state_name,b.state_name);
}
};
void main() 
{
char *temp = "Delhi"; 
state statel(temp),state2("Mumbai"),state3("Nagpur"),S1,S2;
S1.Replace(state1, state2);
S2.Replace(S1,state3);
S1.display();
S2.display();
}

Аnswer:
There is semicolon(;) after state (char *s ); which will result into syntax error.In case, there is no semicolon(;) after state(char *s),then the output will be:
DelhiMumbai
DelhiMumbaiNagpur

Question 10:
What will be the output of the following program?

#include<iostrearn.h>
#includeCctype.h>
#include<conio.h>
#include<string.h>
void ChangeString(char Text[],int SCounter)
{
char *Ptr = Text;
int Length = strlen(Text);
for(;Counter<Length-2;Counter+=2;Ptr++)
{
*(Ptr+Counter)=toupper(*Ptr+Counter);
}
}
void main()
{
int Position = 0;
char Messaged = "Pointers Fun"; 
ChangeString(Message,Position); 
cout<<Message<<"@"<<Position;
}

Аnswer:
Output
PoiQteMs Wun |@10

Question 11:
Give the output of the following program segment. (Assume all required header files are included in the program).

#include<iostream.h> 
void main()
{
int a = 32,*X = &a; 
char ch = 65,&eco = ch; 
eco += a;
*X += ch;
cout<<a<<','<<ch<<endl;
}

Аnswer:
Output
129, a

Question 12:
Identify the syntax error(s), if any, in the following program. Also, give reason for errors.

void main()
{
const int i = 20;
const int *const ptr = &i;
(*ptr)++; 
int j=15; 
ptr = &j;
}

Аnswer:
In the given program, there are two errors:
(*ptr) + + cannot modify const object
ptr = &j cannot modify const object

Question 13:
Give the output of the following program (assume all required header files are include in the program).

void main() 
{
int array[] = {2,3,4,5};
int *arptr = array;
int value = *arptr;  
cout<<value<<"\n";
value = *arptr++;
cout<<value<<"\n";
value = *arptr;
cout<<value<<"\n";
value = *++arptr;
cout<<value<<"\n";
}

Аnswer:
Output
2
2
3
4

Question 14:
Give the output of the following program segment (assume all required header files are included in the program).

void main()
{
char *s = "GOODLUCK"; 
for(int x=strlen(s)-1;x>=0;x--)
{
for(int y=0;y<=x;y++) 
cout<<s[y]; 
cout<<endl;
}
}

Аnswer:
Output
GOODLUCK
GOODLUC
GOODLU
GOODL
GOOD
GOO
GO
G

Question 15:
Give the output of the following program segment (assume all required header files are include in the program)

void main()
{
char *NAME = "a ProFile"; 
for(int x=0;x<strlen(NAME);x++) 
if(islower(NAME[x])); 
else
if(isupper(NAME[x])) 
if(x%2 != 0)
NAME[x] = tolower(NAME[x-1]); 
else
NAME[x]--; 
cout<<NAME<<endl;
}

Аnswer:
a Orooile

Question 16:
Find the output of the following program:

#include<iostream.h>
#include<conio.h> 
void main() 
{
int *PointerArray[10]; 
int marks[]={75,68,90,34,0,10,90,65}; 
for(int I=0;marks[I]!=0;I++)
{
PointerArray[I]=&marks[I]; 
*(PointerArray[I])+=5;
}
int index=0; 
while(index<I)
{
int p=*(PointerArray[index]); 
if(p>60)
cout<<p<<","; 
index++;
}
getch();
}

Аnswer:
Output
80, 73, 95,

Question 17:
A C++ program contains following declaration: static int x[5] =    {5, 20, 30, 50, 70};

  1. What is the meaning of x?
  2. What is the meaning of (x + 2)?
  3. What is the value of *x?
  4. What is the value of (*x + 2)?
  5. What is the value of *(x + 2)?

Аnswer:
Let us assume the base address or the starting address of the array as 1000, i.e
chapterwise-question-bank-cbse-class-12-computer-science-c-pointers-(175-1)
Here, each box is taking 2 bytes because array contains integer type variables and int takes 2 bytes.

  1. x represents an array of size 5 and also the base address of array, i.e. 1000.
  2. It will increase the value of x by 4 bytes, because x + 2 = x + (size of int) *2 = 1000+2*2 =1004
  3. *x means value at the address contained in x[0], i.e. 5.
  4. (*x+ 2)— *(1000)+ 2 [because *(dercfcrcnce operator) has higher priority than binary operators] =5+2=7
  5. *(x+ 2)= *(1000+ 2x 2)= *(1004)= 30

Question 18:
Give the output of the following program:

void main()
{
char *NAME="CoMPutER"; 
for(int x=0;x<strlen(NAME);x++) 
if(islower(NAME[x]))
NAME[x] = toupper(NAME[x]); 
else if(isupper(NAME[x])) 
if(x%2 = 0)
NAME[x] = to!ower(NAME[x]); 
else
NAME[x] = NAME[x-1]; 
puts(NAME);
}

Аnswer:
Output
cOmmUTee

Question 19:
Write the output of the following program:

#include<iostream.h> 
static int i = 100; 
void Print(char *p)
{
p = "Pass";
cout<<"Value is "<<p<<endl;
}
void main()
{
char *q = "Best of Luck";
Print(q);
cout<<"New value is"<<q;
}

Аnswer:
Output
Value is Pass
New value is Best of Luck

Question 20:
Give the output of the following program:

void main()
{
char *Text[2] = {"Two", "six"}; 
for(int C=0;C<2;C++)
{
for(int D=0;D<strlen(Text[0]);D++) 
if(islower(Text[C][D]))
cout<<(char)toupper(Text[C][D]); 
else
if(isupper(Text[C][D])&&(D%2=0)) 
cout<<(char)tolower(Text[C][D]); 
else
cout<<Text[C][D]; 
cout<<D<<endl;
}

Аnswer:
Output
tW03
SIX3

Question 21:
Find syntax error(s), if any, in the following program:

#include<iostream.h> 
main()
{
int x[5],*y,z[5] 
for(i-0;i<5;i++)
{
x[i] = i; 
z[i] = i+3; 
y = z; 
x = y;
}
}

Аnswer:

#incl udeCiostream.h> 
main()
{
int x[5], *y, z[5]  //Errorl 
for(i=0;i<5;i++)  //Error2 
{
x[i]=i; 
z[i]=i+3; 
y=z; 
x=y;
}
}
Error 1 Semicolon missing (;)
Error 2 Declaration syntax error, i is not declared

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