Programming Tips

This is a place for sharing some practical programming tips.

add by small steps: When adding features/functionality etc. into your code, do it by very small steps and test after each step. Do NOT add multiple things at once. If you add 3 features at once and then find out the program doesn't work, you will have an extremely hard time finding out the bug because it may be in feature 1, feature 2, feature 3 or ANY COMBINATION of them, so you may very well never find the bug. If you instead test after adding each step, you find potential bugs immediately which will make fixing them very quick and easy.
no indentation for temporary code: Tiny "workflow" tip: when adding new code, keep it unindented so that you know it's the newly added code and can delete it at any time. Only when you test the added code, indent it correctly to incorporate it as the final code. Of course, this fails in languages where indentation matters (Python cough cough) but similar effects can be achieved e.g. by adding many empty lines in front of/after the temporary code.
comments/preprocessor to quickly hide code: It is a basic trick to comment out lines of code we want to temporarily disable. However preprocessor may work even better, e.g. in C if you want to be switching between two parts of code, instead of constantly commenting one part and uncommenting the other just use #if 0 and #else directives around the two parts. You can switch between them by just changing 0 to 1 and back.