An array is a way to store values of the same type.  If I need
to store scores for 100 students, I could declare 100 variables,
but it would be much simpler to declare a single variable with
100 places in it (called "elements").

There are two ways to declare arrays in Java:

Do it this way if you know what the elements will be already:
        double [] temps={99.5,44.7,86.3,100.3};
        //alternatively, you can do:
        //double temps[]={99.5,44.7,86.3,100.3};

Otherwise, do it this way:
        double [] temps=new double[4]; //where 4 is the number of
        //elements in the array

Note that arrays are indexed from 0 to the number of elements in
the array -1.

In the first example above:
        temps:
        99.5    44.7    86.3    100.3
        [0]     [1]     [2]     [3]

We refer to each element by its "index" or "subscript".  
Example:
	temps[0]=99.5;

Practice:

How would you declare an array to store 5 integers?

How would you declare an array to store 5 letter grades and
assign the array the values 'A' 'B' 'C' 'D' and 'F'?

For Loops and Arrays often go together, because you can
use the for loop control variable (the counter) to index
the array.

For example, given:

int scores[]={96,85,73};


To print these scores, you could write:

System.out.println(scores[0]);
System.out.println(scores[1]); 
System.out.println(scores[2]); 


Or you could use a loop instead:

for (int counter=0;counter<3;counter++)
	System.out.println(scores[counter]);