Introduction To ARRAYS

Introduction To 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 or subscript in brackets after the array name.
For example,  Salary [10]  represents the salary of the 10th employee while the
complete set of values is referred to as an array,the individual values are called elements. Arrays can be of  any variable type.

One -Dimensional Arrays :
   A list of items can be given one variable name using only one subscript and such a variable
is called Single-subscripted variable or a One-Dimensional array.
 In mathematics we often deal with variables that are single-subscripted.For instance, we use the equation
A = Xi
n=0
calculate the average of n values of x. the subscripted variable Xi refers to the ith element of X.In C,
single-subscripted variable Xi can be expressed as X[1],
 X[2], X[3],...............X[n]
  The subscript can begin with number 0.that is allowed.For example, if we  want to represent a set of five numbers, say(35,40,20,57,19) by an array variable number,then we may declare the variable number as follows
 int  number [5];
 and the computer reserves five storage locations as
shown below.
    Number[0]
    Number[1]
    Number[2]
    Number[3]
    Number[4]
values to the array elements can be assigned as follows:
    number[0]=35;
    number[1]=40;
    number[2]=20;
    number[3]=57;
    number[4]=19;
 this would cause the array number to store the values as
 shown below:

        number[0]       35
        number[1]       40
        number[2]       20
        number[3]       57
        number[4]       19

  these elements may be used in programs just like any other
C variable. Forexample, the following are valid statements:
          a= number[0] +10;
          number[4]= number[0] + number[2];
          number[2]= X[5] + Y[10];
          value[6]= number[i]* 3;
 subscript of an array can be integer constant,integer variables like i , or expressions that yield integer. C  performs no bounds checking and therefore, care should be exercised to ensure that the array indices are within the declared limits.