Yep, RegExp too, you are right. The only caveat that might comes to my mind is dealing with foreigner objects ( through plugins such Java applets and stuff ) where maybe there is a difference, but I've no memory of any sort of real-world use case based on the fact that `new` was mandatory.
Indeed if you try even minifiers, you'll notice that code like this ```js this.bla = new Object(parent.foreignObject); ``` will be minified as ```js this.bla=Object(parent.foreignObject); ``` On Fri, Jun 12, 2015 at 11:09 PM, Benjamin Gruenaum <benjami...@gmail.com> wrote: > Thanks, Array and Function (as well as RegExp) actually directly specify > that calling them with and without new produces equivalent results where > `Object` doesn't and actually has a hole (in what it _may_ do to host > objects). > > It's just baffling that `Object` is defined so differently. I wonder if > there are old browsers that differ on this, or there is a bigger reason for > this behaviour. > > On Sat, Jun 13, 2015 at 12:05 AM, Andrea Giammarchi < > andrea.giammar...@gmail.com> wrote: > >> I think historically `Array`, `Function`, and `Object` can be used with >> or without `new` and the result is exactly the same ... since, about, ever. >> >> Agreed if that's actually indeed the case, we could have just one >> definition for those 3 constructors (not just Object) >> >> Regards >> >> On Fri, Jun 12, 2015 at 10:19 PM, Benjamin Gruenaum <benjami...@gmail.com >> > wrote: >> >>> Ok, so I gave this a few hours in the open. >>> >>> So, I'm looking at the ES5 specification (also checked the current ES >>> draft which is similar) at the definition of what new Object and Object do. >>> To my surprise: >>> >>> - `new Object` describes a whole algorithm of how the object constructor >>> works - treating what happens with different kinds of values. Basically >>> calls `ToObject` on non objects - identity on objects and builds on null >>> and undefined. >>> - `Object` has a special first step for null and undefined where it >>> builds an object and then calls `ToObject` on primitives and identity on >>> objects. >>> >>> After reading the description a few times - they seem identical. >>> However, clearly from the spec they do *something* different. For example >>> in Array - calling new Array is specified as the function call Array(…) is >>> equivalent to the object creation expression new Array(…) with the same >>> arguments.` >>> >>> The only difference I've been able to identify with the help of a friend >>> is that the behaviour can be different on host objects. Where `Object` must >>> return the same host object and `new Object` _may_ return the same host >>> object. >>> >>> I've taken a look at the ES3 specification and it too uses the same >>> definition so I suspect this is something that has been there for a long >>> time. >>> >>> - Why are `Object` and `new Object` specified differently? >>> - If there is no actual reason, can the definition be simplified for >>> the next version of the spec? (I think simplifying the spec is important >>> and possibly underrated) >>> >>> Sorry if I'm missing something obvious. >>> >>> Originally asked on Stack Overflow - >>> http://stackoverflow.com/q/30801497/1348195 >>> >>> _______________________________________________ >>> es-discuss mailing list >>> es-discuss@mozilla.org >>> https://mail.mozilla.org/listinfo/es-discuss >>> >>> >> >
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