Sometimes, in debugging, we want program stopped when some variables are accessed or modified. To set traditional breakpoints for this case, you have to spend a lot of time to find all places to access or modify variables. It’s even harder when variables are passed to other object or the derivation hierarchy is complicated. In this case, watchpoint is a good helper.
In Eclipse, it’s quite easy to set watchpoint. In “Outline” view, you can right click on the variable you want to want and select “Toggle Watchpoint“. 
Then you can find a new watchpoint in “Breakpoints” view. You can see the icons of breakpoint and watchpoint are different.
By default, watchpoint will be hit when accessing or modifying the watched variable. To change it, we can simply right-click the watchpoing and select “Breakpoint Properties…“.
