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Struct student 

{ 

intAdmno; 

charname[30]; 

int mark[6]; 

}

(a) #include<iostream>

using namespace std;

int main()

{

struct student

{

char name[40];

int roll;

int marks[6];

}
S1;

count<<"Enter name";

cin>>S1.name;

cout<<"Enter roll no";

cin>>S1.roll;

cout<<"Enter 6 marks";

for (int i=0;i<6;i++)

cin>>S1.marks[i];

cout<<"The details are given below";

cout<<"\n Name:"<<S1.name;

cout<<"\n Roll No:"<<S1.roll;

for (int i=0;i<6;i++)

cout<<"\n mark"<<i + 1<<S1.marks[i];

return 0;

}

(b) #include<iostream>

using namespace std;

int main ()

{

int main [50],i,j,*ptr,n,temp, ptr = mark;

cout<<"Enter how many student";

cin>>n;

for(i=0;i<n;i++)

{

cout<<"Enter mark"<<i+1<<";";

cin>>*(ptr++)

}

for(i=0;i<n-1;i++)

for(j=i+1;j<n;j++)

if(mark[i]>mark[j])

{

temp = mark[i];

mark[i] = mark[j];

mark[j] = temp;

} ptr = mark;

cout<<"The marks in descending order";

for(i=0;j<n;i++)

cout<<*(ptr++)<<endI;

}

Run time allocation of memory is new

struct students 

{ 

short rno; 

char name[25]; 

float height; 

};

Employee struct 

{ ecode int; 

char name[25];

salary double; 

}

Allocating memory for an integer array of 15 elements.

student s = {19,“aysha”,75};

Array-:

An array is a collection of elements with same data type Or with the same name we can store many elements, the first or second or third etc can be distinguished by using the index(subscript). The first element’s index is 0, the second elements index is 1, and so on.

To store 100 numbers the array declaration is as follows

int n[100]; By this we store 100 numbers. The index of the first element is O and the index of last element is 99.

Structure -:

But a Structure is a group of different types of Ipgically related data referenced by a single name.

Eg. The collection of details of a student that may contain various data with different data types.

Eg.

struct student

{

int adm_no;

char name[40];

float weight;

};

OR

Correct answer is (a) 4

1. Structure 

2. struct Account 

{ 

int accno; 

char name[30]; 

struct lastdate 

{ 

int day; 

int month;

int year; 

} tdate; 

float 

balanceamt; 

}

(d) p will give the value of the variable ‘x’

‘Only integers can be added or subtracted from pointers’. is  True

The first statement allocates memory of one integer to ptr and initialized it with value 5. The second statement allocates memory of 5 contiguous integers (ie. an array of 5 integers) and stores begining address in pointer ptr.

If the memory allocated using new operator is not de allocated using delete , that memory is left unused and not released for further allocation. Such memory blocks are called orphaned memory. On each execution the amount of orphaned block is increased. This situation is called memory leak. Use delete operator to avoid this.

(a) sptr=new sample;

(b) cin>>sptr->num;

cin>>sptr->str;

Example

#include<iostream>

using namespace std;

struct sample

{

int num;

char *str;

}*sptr;

int main()

{

sptr = new  sample;

cout <<"Enter value for num:";

cin>>sptr->num;

cout<<"Enter value for str:";

cin>>sptr->str;

cout<<sptr->num<<sptr->str;

}

(c) struct sample

{

int num;

char *str;

sample *str;

};

It is accessing the element of a nested structure. S is a structure variable that contains another structure variable dob. ‘month’ is a member of inner structure variable dob. This statement assigns a value 10 to the member month.

Correct answer is (b) .

The array of character pointers is preferred. 

There are two reasons: 

1. An array of pointers makes more efficient use of available memory by consuming lesser number of bytes to store the strings.

2. An array of pointers makes the manipulation of the strings much easier. One can easily exchange the positions of the strings in the array of pointers without actually touching their memory locations.

#include <iostream>

using namespace std;

int main()

{

char *str="";

int len,i,j,flag=0;

cout<<"Enter a string";

cin>>str;

for(i=0;*(str+i)!="\0;i++);

len=i;

for(i=0;j=len-1;i<len/2;i++;j--)

{

if(*(str+i)!=*(str+j))

{

flag=1;

break;

}

}

if(flag==1)

cout<<*It is not palindrome";

else

cout<<"It is palindrome";

}

Student stud = {“Athul”, 17,101, “XII Science”}; The above statement initializes structure variable stud of type student which has data members name, age, roll no, batch.

Both the statements are equivalent as they declare ‘ch’ to be char and initialize it with the value of 67. Since this is the ASCII code for ‘C’ , the character constant also can be used to initialize ‘ch’ to 67.

Character data type accepts and returns all valid ASCII characters. Character data type is often said to be an integer type, since all the characters are represented in memory by their associated ASCII Codes. If a variable is declared as char, C++ allows storing either a character or an integer value.

6 relational operators are binary operators.

C++ provides two unary operators for which only one variable is required. For Example a = – 50;

gets(S1 .name); 

S1.birthday.day=25; 

S1.birthday.month=5; 

S1.birthday. year=1991;

(d) 2005 (add the size of its data type, 2001 + 4)

Binary Operators require two operands:

Arithmetic operators that perform simple arithmetic operations like addition, subtraction, multiplication, division (+, -, * , %, /) etc. are binary operators which requires minimum of two operands.

Relational operators are used to determine the relationship between its operands. The relational operators (, >= , <= , == , !=) are applied on two operands, hence they are binary operators. AND, OR (logical operator) both are binary operators. Assignment operator is also a binary operator (+= , – = , *= , /= , %=).

The assignment S1 = S2 is not right. Because S1 and S2 are different structure variables. C++ does not permit different structure variable assignment.

int * ptr = new int [m*n]; 

where m and n are rows and columns

The operating system takes the responsibility of memory allocation and deallocation without users instruction.

Yes. C++ takes the array name as the address of its first element. That is, the name of an array is actually a pointer pointing to the first element of an array.

The output  is

4020 

4028

Array name +2 gives the address of third element

1. 

*ar = -2

*(ar + 3) = 2 (fourth element) 

Hence *ar + *(ar + 3) = -2 + 2 = 0 

Hence output is 0

2. 

Here ar = 2050 (starting address) 

and * (ar + 4) 

= *(2050 + 4*4) 

= *(2050+16) 

= *(2066) 

= 4 (fth element) 

Hence ar + * (ar + 4) 

= 2050 + 4 

= 2054

(c) structure element using structure pointer variable.

(d) statements (iii) and (iv) are correct

#include 

using name space 

std; intmain() 

{ charstr [ ] = “computer”; 

char * sptr; 

sptr = str; 

cout<< str<< endl; 

cout<< sptr<< endl; 

} 

This code copies the string str to sptr;

Structure specification is merely a data type definition. Memory allocation does not take place during specification. To handle data, memory locations are needed. For memory allocation, variables are to be declared. Hence structure variable is essential for handling structured data in programs.

Arithmetic operators : perform simple arithmetic operations like addition, subtraction, multiplication, division etc.

Unary Operators : Require only one operand .

Example: +, -, * , /, %, >, <, <= , AND,OR

Arithmetic operators : perform simple arithmetic operations like addition, subtraction, multiplication, division etc.

Unary Operators : Require only one operand . 

Example: +, -, * , /, %, >, <, <= , AND, OR

Answer is (d) 66

The structure variables s1 used 33 bytes memory

Correct answer is int * p, n; p = &n;

P = a is the error because p is an integer pointer and can store only address. The correct code is p = &a;

char*name[60];

1. Structure and array: 

Structure and array are both derived data types in C++.: a Structure is a user defined data type while an array is a derived data type. Structure is a collection related data items that can be of different data types. Array is also a collection of elements of same data type Thus both array and structured allow several values to be treated together as a single data object. 

2. Structure and class: 

Structure and class are both user defined data types. Structure is a collection of related data items while class is a collection of data and functions. Hence structure plus related functions form a class.

It is invalid as comma is not allowed in an integer constant. It is valid. Comma in bracket is allowed.

& is used to access reference of a variable.

A structure contains another structure, then it is called nested structure.

The structure vairable doj used 12 bytes and s1 used a total of 45 bytes memory.

After compilation of C++ creates four distinct regions of memory used for distinct functions:

The first area 

(1) is used for storing the compiled code of the program. The second area 

(2) is used for storing global variables of the program. It remains in memory till the program ends. The third region 

(3) known as the stack is used for holding the return addresses of function calls, arguments passed to the function, etc. The last region heap is used for dynamic allocation.

1. Static and dynamic memory allocation. 

2. Every data and instruction data is being executed must be allocated some area in the main memory. The main memory can be allocated in two methods. 

• Static memory allocation 
• Dynamic memory allocation

When the amount of memory to be allocated is known in advance and memory is allocated during compilation itself, it is referred to as static memory allocation. When the amount of memory to be allocated is not known in advance and it is required to allocate memory as and when required during run time, it is known as dynamic memory allocation.