Why use typeof for identifying a function?

Question

Are there any significant reasons for using

typeof variable === \'function\'

versus

!!variable.call

for d

Answer 1

Check the assumptions in the post (see Gumbo's comment).

typeof /regex/ === 'function'

This returns false in Firefox 3.6.13.

Just for amusement, Firefox 3.6.13:

typeof /regex/                    // "object"
/regex/ instanceof RegExp         // true
/regex/.constructor.name          // RegExp
(function () {}).constructor.name // Function

IE8:

typeof /regex/                    // "object"
/regex/ instanceof RegExp         // true
/regex/.constructor.name          // undefined
(function () {}).constructor.name // undefined

Chrome 9:

typeof /regex/                    // "function"
/regex/ instanceof RegExp         // true
/regex/.constructor.name          // "RegExp"
(function () {}).constructor.name // "Function"