seanmonstar

How I Name Boolean Variables

Naming variables is important stuff. Besides the classic “classes should be nouns, methods should be verbs” stuff, I find another very common naming convention I use is in naming my Booleans.

Particulary, I like to name them so they are a question. You can read the name of the variable, and feel you were asking a question about some object. And the question must be a yes/no question for it to work. No howAreYou variables. I make sure that it truly does sound like a question. I don’t like using single word adjectives or adverbs, like running or recommends. I’ll add is or has to make it sound like a question.

Some examples:

server.isRunning
book.isRecommended
dog.canBark
table.shouldReplace

It’s much easier to tell by looking at them that they are boolean values. Whereas, something like item.likes could actually be a number, of how many people liked the item. item.isLiked tells me that something liked the item. It’s going to be a yes or no answer to my boolean question.