I've worked with code in the past where the previous developers didn't understand that there was a difference between an integer in a string (i.e. var x = '10';) and an integer (i.e. var x = 10; ). In some ways weak typing and automatic type conversion is quite dangerous because it can encourage beginners to adopt bad practice and be non the wiser.

Edit: Changed 'In some ways duck typing' to 'In some ways weak typing' as rightly pointed out below.

> duck typing and automatic type conversion

It's weak typing (or equivalently "automatic type conversion" as you say) that is to blame. "Duck typing" - also "structural polymorphism", "subtyping polymorphism", know in OCaml as "polymorphic variants" and adopted as a default by Go's interfaces semantics - would only enable "'10' + 10" if String type would have a method "+(x:Number)", which most likely is not there, or if it is it's explicitly laid out.

It's weak typing - ie. language trying to coerce elements of expressions to the types which make the whole expressions make sense, with implicit rules that no one ever reads - that's dangerous.

Sorry for being this pedantic, but while I'd like to see less weak typing in languages (outside of some specific domains, like AWK) I'd also would like to see more "duck typing", because it's more convenient than nominative polymorphism and exactly as safe.

Sorry, you're absolutely right! I had confused the two when writing my post.