https://stackoverflow.com/questions/964910/is-javascript-an-untyped-language

strong/weak can be thought of in relation to how the compiler, if applicable, handles typing.

Weakly typed means the compiler, if applicable, doesn’t enforce correct typing. Without implicit compiler interjection, the instruction will error during run-time.

“12345” * 1 === 12345 // string * number => number

Strongly typed means there is a compiler, and it wants you an explicit cast from string to integer.

(int) “12345” * 1 === 12345

In either case, some compiler’s features can implicitly alter the instruction during compile-time to do conversions for you, if it can determine that is the right thing to do.

Thus far, JavaScript can be categorized as Not-Strongly-Typed. That either means it’s weakly-typed or un-typed.