a variable of array type holds a reference of object
array are commonly used in computer program to organize data so that a related set of values
array are using zero base indexing it start with 0.
all component of array have same type, two different types doesn't use in single array
if array are store 10 quantities its index value varies from 0 to 9.
it stores 1st quantity value in index value 0 and this process will same till index value 9.