ARRAYS

ARRAYS:

An array is a group of related data items that share a common name.For instance,we can define an array name salary to represent a set of
salaries of a group of employees. A particular value is indicated by writing a number called index number of subscript in brackets after the array name.

For example: salary[20];//salary contains maximum of 20 charaters
Array range will be 0 to n.
There are two types of arrays:
1.one dimentional arrays
2.two dimentional arrays

Array declration:
ex: int marks[20];

Entering data in array:
ex: for(i=0;i<=19;i++)
{
printf("\nenter marks");
scanf("%d",&marks[i]);
}

Reading data from an array:
ex: for(i=0;i<=19;i++)
sum=sum+marks[i];

a) An array is a collection of similar elements.
b) The first element in the array is numbered 0,so the element is 1 less than the size of the array.
c) An array is also known as a subscripted variable.
d) Before using an array its type and dimension must be declared.

More on Array(Array Initialisation):

ex: int num[6]={2,4,6,8,10,12};
int n[]={2,3,4,5,6};
float p[]={12.3,34.2};
Note:
a) Till the array elements are not given any specific values,they
are supposed to contain garbage values.
b) If the array is initailsed where it is declared mentioning the dimension of the
array is optional as in the 2nd example above.


Initialising A 2-Dimensional Array:

how to intialise atwo dimensional array?

int stud[4][2];

above initialisation tells that there will be 4 rows and 2 columns.
in other words 4 different numbers of students and thier marks and other thing should be 2 character.

ex: int stud[4][2]={{1234,56},{1345,67},{1456,78},{1567,90}};
it can be written i other form
ex: int stud[4][2]={1234,56,1345,67,1456,78,1567,90};

In Matrix Array is represented as:

ex: int a[3][3];// 3*3 3 rows and 3 columns