When I started my journey as a computer programmer, I had written my code in various way. In most cases, I translated requirements into specific conditions and statements, but I hadn’t taken too much care of readability or quality of my code. “It works, that’s it” – and the code base grew and grew in time. Thousands of written methods later, I had discovered that a lot of these little pieces of logic could look better if I reverse some condition within them. Unconsciously, I’ve started following the rule which I had later called the “fail fast” rule, and subsequently “return early".
I realized I hadn’t had the one preferred way to check conditions within the single method. Sometimes I let execution if the expression was true. Another time I had waited for the false result to show the error message before the main part of the code was executing. In my head, I discovered various styles of checking conditions.