Note: You are looking at a static copy of the former PineWiki site, used for class notes by James Aspnes from 2003 to 2012. Many mathematical formulas are broken, and there are likely to be other bugs as well. These will most likely not be fixed. You may be able to find more up-to-date versions of some of these notes at http://www.cs.yale.edu/homes/aspnes/#classes.
Syntactic sugar is a feature in a programming language that provides no new functionality that can't be gotten from using other features, but that makes writing (and sometimes reading) code easier. For example, in C, any reasonable compiler will produce identical machine code for each of these three lines:
2 x += 1;
3 x = x + 1;