Arrays
Before reading this tutorial, you should have knowledge of
loop statements.
An array is a collection of several data items of the same
data type. It consists of several contiguous memory locations storing data. It
removes the cumbersome task of defining separate variables for each data item.
A single variable can be used to store one or more data items. For example, if
you want to store ages of 10 students of a class, you can easily declare an
array of integer type of size 10 instead of declaring 10 variables of integer
type each storing age of a student. The general form of the single dimension
array is:-
type variable_name[size];
The type is the base type of the array and which is the type
of each of the element of the array. The size is the no of the elements in the
array. The variable_name is the name of the identifier holding the array. For
example,
int age [10];
The age is an array of type integer whose size is 10. It can
hold 10 data values. The specific element in the array can be accessed
using an index. An index is the offset from the first element of the array. For
example, first element has an index of 0 while the third element has an index
of 2. The integer age has elements from age[0] to age[9]. Here is a program
which illustrates the working of arrays.
| #include<iostream> using namespacestd |
#include<iostream>
using namespace
std;
int
main ()
{
int age[10];
int i,sum=0, avg=0;
int max=0,min=100;
for(i=0;i<10;i++)
{
cout << "Enter the age of the student " << i+1 <<endl;
cin >> age[i];
}
for(i=0;i<10;i++)
{
int age[10];
int i,sum=0, avg=0;
int max=0,min=100;
for(i=0;i<10;i++)
{
cout << "Enter the age of the student " << i+1 <<endl;
cin >> age[i];
}
for(i=0;i<10;i++)
{
sum=sum+age[i];
if(age[i]>max)
{
max=age[i];
}
if(age[i]<min)
{
min=age[i];
}
}
avg=sum/10;
cout << "Average age of the students of the class : " << avg
<< endl;
cout << "Maximum age of the student of the class : " << max
<< endl;
cout << "Minimum age of the student of the class : " << min
<< endl;
return(0);
}
The result of the program is:-
In the program the array is declared by the statement
int age[10];
age is the identifier of the array which is of type integer
and whose size is 10. In the for loop user is asked to enter the age of the
student, the age is stored in the element of the array by the statement
cin >> age[i];
here i is the index of the array. The index starts from
0. In the next for loop, average age, minimum age and maximum age of the
students is calculated. Each element is accessed by index i. The sum of the
elements of the array is calculated by the statement
sum=sum+age[i];
age[i] is the (i+1)th element of the array. The maximum age is
calculated by the if statement
if(max>age[i])
{
max=age[i];
}
The minimum age is calculated by the another if statement
if(min<age[i])
{
min=age[i];
}
The average is calculated by the statement
avg=sum/10;
The total no bytes used to store an array is equal to
Total bytes=size of(base type)×size of array.
Initializing Arrays
The arrays can be
initialized by giving the initial values in a list and enclosed in
curly brackets, which is placed after the equal sign which is put after
the declaration of the array. For example,
int age[5]={12,13,10,24,15};
elements of the array
have values 12, 13, 10, 24, 15. The elements age[0] has value 12 and
age[4] will have 15. If the elements of the array are not initialized
then they take some garbage value before they are assigned to some
specified value. There is also another way of initializing all the
elements of the array to be zero. For example,
int age[5]={0};
will initialize all the
elements of the array age to be zero. If you want some of the elements
to be initialized with specific value and rest of the values to be
zero then here is an example.
int age[5]={12,13};
The elements age[0] and
age[1] will be initialized to 12 and 13 respectively and rest of the
elements will be initialized to zero.
Null Terminated Strings
The most common use of
one dimensional array is for character strings. The null terminated
string is a character array with a null
character at the end. The characters form the string with a
null character indicating the termination of the string. A null
terminated string can be declared as
char name[10];
it will hold 10
characters with a null at the end. The size of the array can be more
than the length of the array. The array can be initialized as
char name[10]={'j','e','s','u','s'};
The first 5 elements
are initialized and rest elements are null characters. Here is a
program which calculates the length of the string.
#include<iostream>
using namespace std;
int main()
{
char name[15];
int i=0;
cout << " Enter your name " << endl;
cin >> name;
while(name[i]!='\0')
{
i++;
}
cout << "Lenght of the name is : " << i << endl;
return(0);
}
The result of the program is
The character array is declared by the statement
char name[15];
The length of the name can be at most 15. The arrays is assigned by taking the input from the user by the statements
cout << " Enter your name " << endl;
cin >> name
Variable name is
assigned the string entered by the user. Each element of the array is
referenced and checked whether it is null or not by the statement
while(name[i]!='\0')
Until a null character is not encountered variable i is incremented by the statement
i++;
When a null character is encountered while loop is terminated and length is printed by the statement
cout << "Length of the name is : " << i << endl;
Multidimensional Arrays
The multidimensional
arrays are arrays of arrays. The general form of a multidimensional array is: -
type variable_name[Size1][Size2]..[Size n];
The two dimensional array can be declared as
int age[2][5];
this array has two rows and 5 columns. The three dimensional array can be declared as
int age[2][3][5];
When an element of the
array of n dimensional is referenced it uses n index values. For
example first element of a two dimensional array declared above is
referred as age[0][0] as the index starts from zero and last element is
referred as age[1][4]. Here is a program which calculates the average
of the elements of the row of the two dimensional array.
#include<iostream>
using namespace std;
int main ()
{
int age[2][5]= { {12,13,14,15,15}, { 12,16,17,13,12}};
int i,j;
int sum=0,avg=0;
for(i=0;i<2;i++)
{
for(j=0;j<5;j++)
{
sum=sum+age[i][j];
}
avg=sum/5;
cout << "Average of the elements of the row " << i+1
<< " is " << avg << endl;
sum=0;
}
return(0);
}
The result of the program is: -
The program initializes and declares the two dimensional array by the statement
int age[2][5]= { {12,13,14,15,15}, { 12,16,17,13,12}};
Elements of the first row and second row are initialized as {12,13,14,15,15} and
{ 12,16,17,13,12} respectively. The elements are accessed using the statement as
sum=sum+age[i][j];
age[i][j] refers to the
element of row i and column j. This statement calculates the sum of
the elements of the row. After the sum of the elements of a row is
calculated then average is calculated by the statement.
avg=sum/5;
sum is again initialized to zero. Then again the same process repeats for the second row.
After an introduction of arrays, let us move on to discuss pointers.
//Name : Sumonto Kumer Ghosh
ReplyDelete//ID : 201410848
//Batch : 45 th
//Write a program performing as calculator which allows all Arithmetic Operators with operand
#include
using namespace std;
class square
{
public:
int height;
int width;
int area();
};
int square::area()
{
return height*width;
}
int main()
{
square obj;
obj.height = 20;
obj.width = 10;
cout<<"Area = "<<obj.area()<<endl;
return 0;
}
//Name : Sumonto Kumer Ghosh
ReplyDelete//ID : 201410848
//Batch : 45 th
//calculate square and cube of given number using inline function
C++ program using class to calculate square and cube of given number using inline function
#include
class power
{
public:
inline int square(int n)
{
-----------------------------
-----------------------------
}
inline int cube(int n)
{
-----------------------------
-----------------------------
}
};
void main()
{
-------------------------------
-------------------------------
}
//Name : Sumonto Kumer Ghosh
ReplyDelete//ID : 201410848
//Batch : 45 th
#include
#include
class line
{
public:
inline float multi(float c,float d)
{
return(c*d);
}
inline float cube(float c)
{
return(c*c*c);
}
};
void main()
{
line obj;
float c1,d1;
clrscr();
cout<<"\n Enter Two Value ";
cin>>c1>>d1;
cout<<" Multiplication is :"<<obj.multi(c1,d1)<<endl;
cout<<" Cube of val1 is :"<<obj.cube(c1)<<endl;
cout<<" Cube of val2 is :"<<obj.cube(d1)<<endl;
getch();
}
//Name : Sumonto Kumer Ghosh
ReplyDelete//ID : 201410848
//Batch : 45 th
//C++ program to calculate simple interest amount use default value for rate
Write a C++ program using class to calculate simple interest amount use default value for rate.
#include
using namespace std;
main()
{
float SI=0,p,t,r;
cin>>p>>t>>r;
SI=((p*t*r)/100);
cout<
using namespace std;
float interest(float q,float s,float r);
main()
{
float q,,r,SI=0;
cin>>q>>s>>r;
interest(q,s,r);
}
float interest(float x,float y,float z)
{
float SI;
SI=((x*y*z)/100);
cout<<SI;
}
//Name : Sumonto Kumer Ghosh
ReplyDelete//ID : 201410848
//Batch : 45 th
//C++ program to find area of triangle, circle,and rectangle using function overloading
Write a C++ program to find area of triangle, circle,and rectangle using function overloading
#include
Float area(int r)
{
cout<>r;area(r);
cout<>b>>h;
area(b,h);
cout<>l>>br;
area(l,br);
getch();
return 0;
}
//Name : Sumonto Kumer Ghosh
ReplyDelete//ID : 201410848
//Batch : 45 th
#include
class power
{
public:
inline int square(int s)
{
return s*s;
}
inline int cube(int s)
{
return s*s*s;
}
};
void main()
{
int s,r;
power p;
clrscr();
cout<<“\nEnter the Number: \s” ;
cin>>n;
r=p.square(s);
cout<<“\nSquare of “<<s<<” = “<<r<<endl;
r=p.cube(s);
cout<<“\nCube of “<<s<<” = “<<r<<endl;
getch();
}
//Name : Sumonto Kumer Ghosh
ReplyDelete//ID : 201410848
//Batch : 45 th
//check strange number using inheritance
#include
using namespace std;
//base class
class strange
{
public:
void setdigit(int d)
{
digit=d;
}
protected:
int digit;
};
//derived class
class number : public strange
{
public:
int i,j,t=1,d;
int devide()
{
while(d!=0)
{
j=d%10;
d=d/10;
for(i=2;i>p;
nmb.setdigit(p);
nmb.check();
}
//Name : Sumonto Kumer Ghosh
ReplyDelete//ID : 201410848
//Batch : 45 th
#include
#include
using namespace std;
class CheckStrnge
{
public:
int strange (int s)
{
int r,n,p=1,i;
while(s!=0)
{
r=s%10;
n=s/10;
for(i=2 ;i>number;
Str.strange(number);
}