As we write functions or move code from one function to another, we cut and paste and put the code in different contexts. Very often, we will not have the same names for the variables. Therefore it is very easy to go wrong and have code that uses variables that don't actually exist - good as easy to detect - or worse, use the name of a variable that has another existing purpose. We can either use that variable with the wrong value, or overwrite it!
Use codetools::findGlobals(, FALSE) or CodeAnalysis::getGlobals() which is slightly more accurate.
- when writing functions
- when refactoring/reorganizing code