Java Arrays Test

Array

a contiguous chunk of memory to store an ordered list of related data

declare

reserving or requesting memory for the array

populate

to put data into an empty array

traverse

visiting or accessing every element in the array

initializer list

allows an array to be declared and initialized in one statement

how to declare array

datatype [] arrayName = new datatype [#ofElements];

int [] cats = new int [2];

.length

how many elements are in an array

.length - 1

prints the last element of array

Once an array has been instantiated…

the number of elements cannot be changed. 

Array of Objects

collection of object references

When an array of objects is instantiated…

• it is filled with null. 

• Each object, like a Coin object, needs to be instantiated. 

• The references need to be copied into the array. 

Is it possible to have an array of objects where some of the elements are null and some of the elements have references pointing to objects?

YES