JS: Filter array only for non-empty and type of string values

Question

I am trying to filter an array like this:

array.filter(e => { return e })

With this I want to filter all empty strings including undef

Answer 1

const justStrings = array.filter(element => 
    (typeof element === 'string' || element instanceof String)
    && element
)

Explanation

To be shure your element is a string you have to check that it isn't a variable type (let str = 'hello') or an instance of String (new String('hello')) because this case would return object by typeof element.

Additionally you have to check if your element exists.