What do you suppose is the value of the arithmetic expression:
data[2] + data[6]
23; data[2] contains a 14 and data[6] contains a 9, the sum is 23.
 
An expression such as data[3] is called
a subscripted variable.
A subscripted variable can be used anywhere an ordinary
variable of the same type can be used.
Since data[3] contains an int it
can be used anywhere an int  variable may be used.
An arithmetic expression can contain a mix of literals, 
variables, and subscripted variables.
For example, if x contains a 10, then
(x + data[2]) / 4
evaluates to (10+14) / 4 == 6. Here are some other legal statements:
data[0] = (x + data[2]) / 4 ; data[2] = data[2] + 1; x = data[3]++ ; // the data in cell 3 is incremented data[4] = data[1] / data[6];
Assume that the array holds values as in the picture. What will be the result of executing the statement:
data[0] = data[6] + 8;