Arrays - Building Java Programs: A Back to Basics Approach - page 465

Then shift the other values to the right:

[0] [1] [2] [3] [4]

list 3 8 9 7 5

list 3 3 8 9 7

In this case, the four individual assignment statements would be the following:

list[1] = list[0];
list[2] = list[1];
list[3] = list[2];
list[4] = list[3];

A more general way to write this is the following line of code:

list[i] = list[i - 1];

If you put this code inside the standard for loop, you get the following:

// doesn't work
for (int i = 0; i < list.length; i++) {
list[i] = list[i - 1];

}

There are two problems with this code. First, there is another off-by-one bug.
The first assignment statement you want to perform would set list[1] to contain
the value that is currently in list[0] , but this loop sets list[0] to list[-1] .
Java generates an ArrayIndexOutOfBoundsException because there is no value
list[-1] . You want to start i at 1 , not 0 :

// still doesn't work
for (int i = 1; i < list.length; i++) {
list[i] = list[i - 1];

}

However, this version of the code doesn't work either. It avoids the exception, but
think about what it does. The first time through the loop it assigns list[1] to what
is in list[0] :

[0] [1] [2] [3] [4]

list 3 8 9 7 5

list 3 3 9 7 5