Review of C++ Exercise 1 - Key

REVIEW OF C++ - CLASS TEST  - KEY

a) Name the header file to which the following belong:  (1)

i. pow( )

ii. random( )

i) math.h   ii) stdlib.h

b) Find the output of the following program: (2)

#include<iostream.h>

void main()

{ long Number = 7583241;

int First=0, Second=0;

do

{ int R=Number%10;

if (R%2==0)

First+=R;

else

Second+=R;

Number /=10;

} while (Number>0);

cout<<First-Second;

}

-2

c) Illustrate the use of local and global variables in C++.  (2)

int x=10; // global variable

void FUNCTION()

{

int x=5;  // local variable

cout<<x<<::x; // displays value in local and global variable

}

d) Differentiate between a Run Time Error and Syntax Error. Also give suitable

examples of each in C++. (2)

Errors occurring during execution of the program is run time error. Eg: logical error in the code like the infinite loop or hardware fault like insufficient memory.

When the rules of the programming language is violated, it results in compilation error.

Eg: cout>>10;

e) Name the header file(s) that shall be needed for successful compilation of the

following C++ code  : (1)

void main ( )

{

char String [20];

gets (String);

strcat (String, “CBSE”);

puts (String);

}

String.h, stdio.h

f) Rewrite the following program after removing the syntactical error(s) if any.

Underline each correction. (2)

# include <iostream.h>

const int Max 10;

void main ( )

{

int Numbers [Max];

Numbers = { 20, 50,10, 30,40 } ;

for (Loc= Max-1 ; Loc > = 0 ; Loc - -)

cout>>Numbers [Loc];

}

g) Find the output of the following program : (3)

# include<iostream.h>

void Withdef (int HisNum = 30)

{

for (int I=20 ; I<=HisNum; I+=5)

cout<<I<<" ";

cout<<endl;

}

void Control (int &MyNum)

{

MyNum+=10;

Withdef(MyNum);

}

void main ()

{

int YourNum=15;

Control (YourNum);

Withdef();

cout<<"Number="<<YourNum<<endl;

}

20 25

20 25 30

Number=25

h) In the following C++ program what is the expected value of MyMarks from

Options (i) to (iv) given below. Justify answer. (2)

#include<stdlib.h >

# include<iostream.h>

void main ()

{

randomize ();

int Marks []= {99, 92, 94, 96, 93, 95}, MyMarks;

MyMarks = Marks [1 + random (2) ];

cout<<MyMarks<<endl;

}

(i) 99                                                                            (ii) 94

(iii) 96                                                                          (iv) None of the above

ii)

i)Differentiate between a Logical Error and Syntax Error. Also give suitable examples

of each in C++. (2)

j) Name the header file(s) that shall be needed for successful compilation of the

following C++ code :  (1)

void main( )

{

char Text[40];

strcpy(Text,”AISSCE”);

puts(Text);}

stdio.h, string.h

K) Rewrite the following program after removing the syntactical error(s), if any.

Underline each correction.  (2)

#include <iostream.h>

const int Size 5;

void main()

{

int Array[Size];

Array = {50,40,30,20,10};

for(Ctr=0; Ctr<Size; Ctr++)

cout>>Array[Ctr];

}

l) In the following C++ program what is the expected value of Myscore from Options

(i) to (iv) given below. Justify your answer.   (2)

#include<stdlib.h>

#include<iostream.h>

void main( )

{

randomize();

int Score[] = {25,20,34,56, 72, 63}, Myscore;

Myscore = Score[2 + random(2)];

cout<<Myscore<<endl; }

(i) 25

(ii) 34

(iii) 20

(iv) None of the above

ii)

m) Find the output of the following program : (3)

#include<iostream.h>

struct POINT

{int X, Y, Z;};

void StepIn(POINT & P, int Step=1)

{

P.X+=Step;

P.Y -=Step;

P.Z+=Step;

}

void StepOut(POINT & P, int Step=1)

{

P.X-=Step;

P.Y+=Step;

P.Z-=Step;

}

void main ( )

{

POINT P1={15, 25, 5}, P2={10, 30, 20};

StepIn(P1);

StepOut(P2,4);

cout<<P1.X<<","<<P1.Y<<","<<P1.Z<<endl;

cout<<P2.X<<","<<P2.Y<<","<<P2.Z<<endl;

StepIn(P2,12);

cout<<P2.X<<","<<P2.Y<<","<<P2.Z<<endl;

}

16,24,6

6,34,16

18,22,28