Types of array

There are mainly three types of array.these are follows.

1. One- Dimensional array
2. Two- Dimensional array
3. Multi- Dimensional array

One-Dimensional array : In C a one-Dimensional array can be declared as int a[10];
by the above statement we are giving an integer type are array named a which can store the element up to 10. In the declaration of an array three things must be encountered:

data-type var_name[size];

We can calculate the length of an array using the given formula:

Length=(UB-LB)+1

LB=Lower bound

UB=Upper bound

Here we have used '+1' in the formula since in general an array is started  from 0 location and to find the exact location of the number '+1' is applied.

Example :Let we have marks of 5 students then it can be show as follows:

Marks[0]=70, Marks[1]=92, Marks[2]=75, marks[3]=72, Marks[4]=82,  

It can be display in row from of array as follows:

And in column from as follows:

 

Hence we can calculate the length of this array.

Length = (UB+LB)+1

=4-0+1

=5

Memory allocation to an array:~As per the data type of the element it is allocate memory space i.e. in C for int 2 bytes, for char 1byte etc.So for the generalized memory space we can drive the expression for each kind data type.

Memory space Required= Length*w

w = byte allocated to that type of data type

For e.g. if we take above given example then from formula

memory apace Reuired =   Length*w  

(for int w=2) 

=5*2

=10

 This array will occur 10bytes in memory

  Let LA be a liner array in the memory of the system. So we can calculate the location of element in the follows manner.

LOC(LAK)=Base(LA)+W(K-lower bound)

Where LA is the linear array, Base address(LA) is denoted the address of the first element of LA and W is the number of words for memory cell for the array LA.

Example: consider an array school,  which record the number of school generated each year from 1947 to 1999. Suppose SCHOOL appears in memory as picture-

Array representation
That is  base[SCHOOL]=500

W=4 words per memory cell for SCHOOL

LOC [1947]=500, LOC[1948]=504,...............

So find the address of array element for the year =1980, So

LOC(SCHOOL[1980]) =Base (SCHOOL)+W(1980-LB)

=500+4(1980 - 1947)

=632

Two dimensional array : A two dimensional array  m * n array is a collection of m.n data elements such that each element is specified by a pair of integers data type, called subscript.
The element of A first subscript J and second subscript K will be denoted by

Aj,k   or A[J,K]

Notes-Detailed study of 2-D array will cover in the next post.

Multi- Dimensional array :-General Multidimensional array are defined analogously an n-dimensional array  M1 * M2 *M3....................Mn, array B is a collection of M1 * M2 *M3....................Mn, data elements can be represents as:

Bk1,k2.......kn or B[k1 k2.......kn]

Operation of array

There are many operation perform by the linear array, there are as follows:

1. Traversal the array
2. Deletion from an array
3. Sorting is an array
4. Insertion in an array
5. Searching in an array
6. Merging in an array

These are all the operation of the array. Now we will be discuss operation one-by-one.

1.  Traversal the array :-By traversing we mean, accessing and/or processing(visiting) of each element exactly once of the array.

Algorithm-: LA (LB, UB, K)

1. [ Initialize counter] Set K=LB
2. Repeat step 3 and 4 while K<=UB
3. [Traverse an element] Apply process to LA[K]
4. [Increase counter] set K=K+1
5. [End of the step 2 loop]
6. Exit

This is the algorithm of the traversing of an array. Now we can see the C-implementation of an array.
Program:-
#include<stdio.h>
#include<conio.h>
void main()  /* Main function */
{
int a[10], i;
clrscr();
printf("enter array value");
for(i=0; i<10; i++)
{ 
scanf("%d", & a[i])
}
printf("the enter array is/n");
for( i=0;, i<10; i++)
{
printf("%d",a[i]);
}
getch();
}
Output of program:-
1
2
3
4
5
6
7
8
9
The enter array is
1
2
3
4
5
6
7
8
9

Insertion in array-After some time: