Pinderkent

A common trait among some of the poorer-quality programming languages, namely PHP and JavaScript, is their use of weak typing. While some developers are convinced that it's acceptable, it's generally a bad idea to have a programming language essentially guess at what the programmer means.

Recently, I saw an article describing some problems within a PHP script caused by automatic conversion. Frankly, these kinds of issues should just not exist. Strong, static typing is clearly a better approach. Although it puts slightly more of a burden on the programmer, the act of manually specifying type conversions leads to higher-quality software, especially if any errors are caught at compile-time, rather than run-time.

JavaScript is another language that employs weak, dynamic typing. I recently saw another article that gives some good examples (under the "2. Plus operator overloading" section) of how this behavior may result in unexpected results, especially for novice developers. But even seasoned professionals still make mistakes, and such conversions should at least be flagged with warnings, if not outright disallowed.

Even though we often deal with fuzzy and incomplete specifications when developing software, we shouldn't bring such uncertainty and guesswork to our communication with the computer itself. We should specify exactly what we mean, even if it does take slightly more typing. Then again, when using languages like Haskell and OCaml, we can clearly see how strong, static typing and type inference can be implemented without overly burdening programmers. Any type conversions that must be manually specified help to force the programmers to think about what they're doing, which in some cases may be quite wrong, especially if a type conversion is necessary.

For the sake of trying to achieve even a moderately reasonable level of quality in our software, especially when programming for a hostile environment like the Internet, we shouldn't resort to languages like JavaScript and PHP that allow for type-related errors to occur so easily. It's even worse when they try to make automatic conversions that result in unexpected behavior. That's just plain unacceptable.