What are the pros of loose typing?

Question

JavaScript is said to be a "loosely-typed" language. This is due to the fact that the runtime allows operations to be performed on operands of different types (via coercion):

var number = 6;
var bool = true;
var result = number + bool; //result is 7

Coming from a mostly statically-typed, strongly-typed background, I am having a hard time reasoning about the benefits of this type of approach. Sure, it can make for some pretty concise syntax, but it also seems like it could cause a nightmare when trying to track down bugs. So, besides conciseness, what are some of the benefits of loose typing and implicit type conversions?

Answer 1

Loosely typed languages have a number of differences which can be taken as advantages:

• There is no need of interfaces. As long as an object has the method name that you need, call that method. Not using interfaces can simplify coding and reduce code size.
• There is no need of generics, for very similar reasons.
• "by type" function overloads are handled more simply If a function needs a string parameter, then just cast the incoming value to a string. If type checking is needed, it can be added there.
• We don't have, or need, classes. The [almost] everything is an object makes passing values around much easier. No need to auto-box, no need to cast values coming out.
• Objects are easily extended without breaking code. You can create an array then drop replace the indexOf method to use one uses the binary search. The end result is smaller, and IMHO, cleaner code.