d+=a; is a the same as d=d+a;
d-=a; is the same as d=d-a;
d*=a; is the same as d=d*a;
d/=a; is the same as d=d/a;

d++; is the same as d=d+1;
d--; is the same as d=d-1;

But d++ is not quiet the sam as ++d;

if  d=3;
x=d++; is the same as x=d; d=d+1;
so x=3; after x=d++; is execute

x=++d; is the same as d=d+1; x=d;
so x=4; after x=d++; is execute

For the above two case: d=4; after x=d++; is execute

I have chinese version web page about basic syntax for java. Please check out [url=http://enjoy.phy.ntnu.edu.tw/mod/resource/view.php?id=6370]Java ????????[/url]
There are similar document in english available on the web. Google will help you find it.

Enjoy you holiday! :-) :D