Can you explain Java pre/post increment/decrement?

If you are only incrementing or decrementing a variable, there's no difference.
i++;
++i;
These are equivalent statements in java.

If, however, you are assigning a value to a variable such as:

array[pos++] = 5;
This means, set the array element at position pos to 5 then increment pos by 1.

array[++pos] = 5;
This means, increment pos by 1 then set the array element at that new pos value to 5.

So if 'pos' was 3, in the first statement we're setting array[3] = 5. In the second statement we're setting array[4] = 5. In either situation, the next line of code will see 'pos' as 4.

This basically means if you are using pre-increment such as ++i this is evaluated before the rest of that code line is. If using post-increment such as i++ this is evaluated after the rest of the code line is.

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