Array

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Array in C

• It is a special variable which is used to store multiple values of same type.

• It share common name for all values.

• It is also known as subscripted variable.

• The element of array is accessed with the help of index value . An index value is positive (+ve) integer value.

• The lower limit of array is zero “ 0 “ and upper limit is ( size -1 ) .

• The index value of array must be started with zero “ 0 “ .

1. It is user defined data type.

➤Advantage of array :-

1. It holds multiple value at a time.
2. It provides simple operation as insertion , deletion, searching , sorting , etc.
3. It shares common name for all values.

➤Disadvantage of array :-

1. It supports static memory allocation.
2. It is a technique in which memory is allocated during compile time . So in  this case memory is wasted due to fixed size of array . It is major drawbacks of  array but it can be avoided with the help of pointer.
3. It stores same type of value but it can be removed with the help of structure.

⟹example:- int  a[10]

10	20	30	40	50	60	70	80	90	100
0           1          2         3         4         5          6         7         8         9

in   the above table “ 0 “ is lower limit / lower bound

and “ 9 “ is the upper limit / upper bound

➤Types of array :-

• One dimensional array / single dimensional array

• Two dimensional array

• Multi  dimensional array

➤One dimensional array :-

• This type of array is use to hold multiple values in a single row.

• The array consists of only one subscript which represents size of array.

⏩syntax:-

<data type> <variable> [size] , <variable>[size],…..

⟹example:-

int a[10] , b[20] ;

float  f[10];

char  str[20];

⏩Initialization :-

⏩Syntax: during declaration time

<data type> <variable name> [size] = { val1, val2 , val3,..}

“here size is optional”

⟹Example:-

int a[5] = { 10, 20 , 30 , 40 , 50 };

int a[] = { 5 , 7 , 22 , 77 , 44 , 99 };

char  s[] = { ‘S’ , ‘A’ , ‘U’ , ‘R’ , ‘A’ , ‘V’ };

char  s[] = “SAURAV” ;

⏩Syntax : after declaration

<variable name> [index] = <value> ;

⟹Example:-

int a[10];

a[0] = 10;

a[1] = 30;

a[2] = 50;

……….

……….

a[10] = 100;

➧Accessing:-

⏩Syntax:-

 <variable> [index]

⟹Example:-

 int a[10] = { 10 , 20 , 30 , 40 , 50 , 60 , 70 , 80 , 90 , 100 }

i.e, 

10	20	30	40	50	60	70	80	90	100
0          1          2         3          4         5         6          7         8          9

a[5] = ? , that is 60.

a [1] = ? , that is 20.

a[ 9] = ? , that is 100.

a[0] = ? , that is 10.

a[3] = ? , that is 40.

P.Example:- Program to input 10 numbers after that printf it.

#include<stdio.h>

#include<conio.h>

void main ()

{

  clrscr();

int a[ 10 ] , i ;

printf( “ enter the 10 numbers “ ) ;

  for ( i = 0 ; i < 10 ; i ++ )

   {

     scanf( “ %d “ , &a[i] );

   }

  printf( “ All elements are :- “ );

   for ( i = 0 ; i < 10 ; i ++ )

   {

   printf( “ %d \n “ , a[ i ] ) ;

    }

  gethc() ;

}

P.example:- Program to input 10 numbers after that print in reverse order.

#include<stdio.h>

#include<conio.h>

 void main()

{

  clrscr();

  int a[ 10 ] , i ;

printf( “ enter the 10 numbers “ ) ;

for ( i = 0 ; i < 10 ; i ++ )

 {

  scanf ( “ %d “ , &a[ i ] ) ;

 }

printf( “ All elements are  \n “  ) ;

 for ( i = 9 ; i >= 0 ; i-- )

{

  printf( “ %d \n “ , a[ i ] );

  }

getch();

}