Detection refers to the practice of determining a value's type. Usually, this will be done with the intention of using that determined type to carry out specific behavior such as falling back to a default value or throwing an error in the case of misuse.
Due to JavaScript's dynamic nature, detecting types is an important practice that can often be a great aid to other programmers. If you can usefully throw errors or warnings when someone is using an interface incorrectly, it can mean a much more fluid and speedy flow of development for them. And if you can helpfully populate undefined, null, or empty values with smart defaults, then it'll allow you to provide a more seamless and intuitive interface.
Unfortunately, due to legacies ...
