Why are methods of String.prototype available to string literals?

Question

This question has come out of another, which concerns the behaviour of console.dir with string literals. In particular, see the comments on my answer.

A

Answer 1

Per the reference literals are converted to objects:

String literals (denoted by double or single quotes) and strings returned from String calls in a non-constructor context (i.e., without using the new keyword) are primitive strings. JavaScript automatically converts primitives and String objects, so that it's possible to use String object methods for primitive strings.