Array

1. Array/scripted variable :

1. An array is a collection of similar element having same datatype.
2. The first element in the array is numbered from zero(0)
   so that last element is one less than the size of the array.
   
3. Before using an array its type and dimension (size)must be declare.
   
4. Array elements are always contineous memory location.
   

One diamensional array :

        Syntax :
 Array declaration-
                      datatype  arrayname[size]

  Here 
       int   :   specifies the type of variable.
       marks :  specifies name of variable(i.e array).
       30    : specifies how many elements of the types int will be in array it is also known as diamension.
        [ ]  : bracket tells the compiler that we are dealing with an array.

Example : 
          int num[6]={ 2,4,5,6,7,8};
          int n[]={2,4,5,6,7,8};
          float press[]={1.1, 1.2, 1.3, 5.6};
          char name[4]={'a', 'b', 'f','\0'};
          char name[5]="bca";

1. program for accept your name ,address and rollno.

  
    void main()
       {
          int rollno;
	   char name[20];
	  char add[30];
           clrscr();
         
          printf("enter your rollno=");
	  scanf("%d",&rollno);

          printf("Enter your name=");
	  scanf("%s",name);

	  printf("Enter address= ");
	  scanf("%s",add);

          printf("roll no=%d\n",rollno);
	   printf("\n NAME=%s"\n address=%s",name,add);

	  getch();
     }

   

1. It is also possible for array to have two or more diamension.The two diamensional array is also called as Matrix.
2. It is a collection of number of one diamensional arrays placed one below the other.
3. 2-D array arranged in Rows and columns from where counting of rows and column begin with zero.

              [ 4 ] [ 2] matrix
             row      column

 
                column 0     column 1 

        row 0   [0] [0]      [0] [1]
        row 1   [1] [0]      [1] [1]
	row 2   [2] [0]      [2] [1]
        row 3   [3] [0]      [3] [1]

           int stud[4][2]={
                            {11,60},
			    {34,56},
			    {45,50},
			    {114,75}
			  };
Method 2-

              int stud[4][2]={11,60,34,56,45,50,114,75};

       void main()
       {
          int a[2][2];
           int i,j;
           clrscr();
                 printf("enter 4 elements for matrix");
		   for(i=0;i<2;i++)
		     {
 			for(j=0;j<2;j++)
		          {
 			     printf("\n enter a[%d][%d]="i,j);
			     scanf("%d"&a[i][j]);
			  }
		     }
		printf("\n matrix :\n");
		for(i=0;i<2;i++)
		    {
			for(j=0;j<2;j++)
			  {
			     printf("%d\t",a[i][j]);
			  }
			printf("\n");
		    }
           getch();
       }


         output : enter 4 elements for matrix
        	  enter a[0][0]=1
	 	  enter a[1][0]=2
         	  enter a[1][0]=3
         	  enter a[1][1]=4

         	matrix :
       			  1   2
        		  3   4

Example : 
         int arr[2][3]={10,20,30,40,50,60};
             or
         int arr[][3]={10,20,30,40,50,60};