C Array Types

In C programming array can be divided into two types :

1. Single dimensional array / Simple array / 1-D array / Linear array

2. Multidimensional array

# Single dimensional array :

When dimension is 1. or when there is a pair of square brackets with the name of array it is known as single dimension array . 

Declaration of single dimension array :

data type , variable name ;

# multidimensional array :

When there are number of pairs of square bracket . or , When there are more than one dimension it is known as multidimensional array . In C programming generally 2- D array are used for the implementation of matrices which is in forms rows and column . In double dimension array first dimension represent the no of rows and second dimension represent the no of columns . 

# Declaration of 2-D array : 

Syntax :    data type array name [ no of rows ] [ no of columns ] ;

                                            Or

                 data type  array name [ m ] [ n ] ;

                    Where  m = no of rows 

                                 n = no of columns

Example :
                 int a [3] [3] ;

1 element = a [0] [0]

2 element = a [0] [1]

3 element = a [0] [2]

4 element = a [1] [0]

5 element = a [1[ [1]

6 element = a [1] [2]

7 element = a [2] [0]

8 element = a [2] [1]

9 element = a [2] [2]

# Input and output with double dimensional array :

# include <stdio.h>

void main ()

{

int a [3] [3] ;

for ( i = 0 ; i < 3 ; i++ )

{

for ( j = 0 ; j < 3 ; j++ )

{

printf ("\n Enter a number:") ;

scanf ("%d", & a[i] [j]) ;

}

} 

#  Output with 2 - D array :

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

{

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

{
printf ("%d", a [i] [j]) ;

printf ("\n") ;

}

}

Array in C

 An array is collection of homogenous element ( of same types ) consist a common property and share  a common name . An array is also known as collection of homogenous element from ( 0 to n-1 ) where n represent the maximum number of element of array .    

An ordinary variable can contain only one value of one types it is not possible to assign more than one value at a single variables.

EXAMPLE :

                     Consider the following variable declaration and initialization .

                     int a = 10 ;

                     Here , a denote a single memory location with a value of 10.

                     If we update the value of variable .

                     a = 20 ;

                     Now the same memory location will contain the value 20 .

                    

Declaration of an array :

An array can be declared as an ordinary variable including the size specification in pair of [ ] bracket.

Syntax :   data type  variable name[ size ] ;

                        or

                data type  variable name [n] ;

              where n = number of elements

EXAMPLE 

                       int a[3] ;

                       In this example the name of an array is " a " which can contain maximum value of 3 at the 3 different locations .

 These 3 different memory location are known as 3 element in c programming , these 3 element are also termed as the 3 subscript . that's why array is also known as " sub scripted variable" . The three different types of variable of a can be written as follows :

                                                    1 element : a [0]

                                                    2 element : a [1]

                                                    3 element : a [2]

Initialization of an Array :

An array can be initialized in three different ways :

(1.)  Element by Element 

    Exam :   int a [3] ;

                    a[0] = 22 ;

                    a[1] = 5 ;

                    a[2] = 66 ;

(2,) Declaration and initialization at same time

    Exam :  int a [3] = { 11 , 22 , 66 } ;

it means 

            a [0] = 11 ;

            a [1] = 22 ;

            a [2] = 66 ;

(3.) Initialization from the user 
    Exam :  
              {
              int i ;
              int a [3] ;
             for ( i = 0 ; i < 3 ; i++ )
             {
             printf ("\n Enter a number:") ;
             scanf ("%d", & a [i]) ;
             }

Output :
              for ( i = 0 ; i < 3 ; i++ )
              printf ("\n %d", a [i]) ;

Program to Access  an array in C :

/* uses of array */

# include <stdio.h>

void main () 

{

int a[5] , i ;

clrscr () ;

for ( i = 0 ; i < 5 ; i++ )

{

printf ("\n Enter a number:") ;

scanf ("%d", & a [i]) ;

}

for ( i = 0 ; i < 5 ; i++ )

printf ("\n %d", a[i]) ;

getch ()

}

When above result is compiled :

Here as from loop statement is compiled then a condition of 5 is check out and a element of a[0] to a[5] is initialized from the user

       
             

 

             

                                                               

Program to find maximum of 5 element of an array in C using for loop statement

/* program of maximum */
# include <stdio.h>
void main ()
{
int a[5],i,max=0 ;
clrscr () ;
for ( i=0 ; i<5 ; i++ )
{
printf ( "\n Enter a number:") ;
scanf ("%d", & a[i]) ;
}
for ( i=0 ; i<5 ; i++)
{
if ( max < a[i] )
max = a[i] ;
}
printf ("\n max = %d", max) ;
getch () ;
}

How to write program to find average of an array of 5 elements

/* Avg of an array */
# include <stdio.h>
void main ()
{
int a[5],i,avg ;
int sum = 0 ;
clrscr () ;
for ( i=o ; i<5 ; i++ )
{
printf ("\n Enter a number:") ;
scanf ("%d"< & a[i]) ;
}
for ( i=0 ; i<5 ; i++ )
sum = sum + a[i] ;
avg = sum / 5 ;
printf ("\n avg= %d", avg) ;
getch () ;
}


DRY RUN ;

sum =0 i=0 0<5
a[0] = 11
i=0 0<5 (TRUE)   i++ = 1
sum = sum + a[i]

similarly
for  i = 1,2,3,4  having true

for i = 5 ( 5<5 ) false