Controlling the Flow of Your Program - Beginning Java Programming: The Object-Oriented Approach - page 143

How It Works
Now take a look at how it works.
1. The application begins by executing the main method, which in this case is the only method.
2. The first statement begins with a for loop.
3. The iterator, named i , begins at value 1 and checks the termination condition. 1 is less than or
equal to 10, so you enter the loop.
4. In the first statement inside the loop, a second int , named doubled , is assigned the value of i *2. In
this first iteration, i = 1, so doubled = 2 .
5. In the next statement of the loop, there is a println command. A line is output to the console that
reads: 1 times two equals 2 . Because the command is println instead of print , you can imag-
ine pressing Enter or Return at the end of the string to create a new line.
6. The program reaches the end of the loop, and because the iteration of the loop is i ++ , 1 is added to
the value of i . The iterator i is reassigned the value of 1+1 or 2.
7. The termination condition is evaluated again. Because 2 is still less than or equal to 10, you will go
through the loop again.
8. The variable doubled is 2*2 or 4 this time.
9. Another line will be output to the console, this time reading: 2 times two equals 4 .
10. This will continue until i ++ = 11 , when the termination condition will evaluate to false and the
loop will not be entered anymore. At that time, the loop will be skipped over and the program will
proceed with the final statement. One final line will be output to the console, indicating the end of
the program.
What Is an enhanced for Loop?
There is an alternate form, called an enhanced for loop, that was introduced specifically for arrays
and other iterable objects. Instead of the index initialized as part of the standard for loop, enhanced
for loops use an iterator. Unlike the index of a standard for loop, the iterator does not require ini-
tialization, termination, or increment, as it will automatically iterate through all elements in the array.
Note that rather than an integer index, the iterator is the same type as the elements in the array or
other Iterable object. From the previous example, this second form would be coded as follows:
for (int i: sales2014){
salesPerStaff[i] = sales2014[i]/staff2014[i];
totalSales2014 = totalSales2014 + sales2014[i];
}
This can be read in English as, “For each int in the sales2014 array, do the following. . .” The
array can contain other data types or objects.