What is an invalidating assignment
These tests will often be quick and easy ones, such as checking that the value of pi you’re using is really what it should be, but if you perform these little checks while you’re working on (and thinking about) that piece of code, you’ll save yourself a lot more effort having to come back later and fix bugs.
You’ll find that you can perform a lot of simple tests very quickly as you go along; once you’re in the habit, you really don’t spend a lot of time doing it.
Reduce dependencies as much as possible A dependency is a connection between two chunks of code, for example, using the same variable, and the more of these your code has, the more things you have to keep track of.
Ensuring these coding principles you can save development time, management time and conquer lots of other bottlenecks which generally arise in later development phases.If you’re feeling keen, writing object oriented code is excellent for this, as this has encapsulation built into the process.Validate your data At some point, someone will feed garbage into your carefully crafted code.You can also use the idea of PHP Design patterns which can speed up the development process by providing tested, proven development paradigms.This article is taken from two articles at programming4with few modifications.