isPrototypeOf is not a function

[Ronald Fischer]

When I evaluate the expression

Array.prototype.isPrototypeOf(arrayrow)

using server-side JavaScript using the Netscape implementation of JavaScript,
I get the error message

Array.prototype.isPrototypeOf is not a function.

What am I doing wrong?

Ronald

[Martin Honnen]

Ronald Fischer wrote:

When I evaluate the expression

Array.prototype.isPrototypeOf(arrayrow)

using server-side JavaScript using the Netscape implementation of JavaScript,
I get the error message

Array.prototype.isPrototypeOf is not a function.

What am I doing wrong?

Probably nothing besides expecting the server-side JavaScript version
you are using to be ECMAScript edition 3 compliant while I think the
last server-side JavaScript version Netscape produced is JavaScript 1.4
and 1.4 doesn't seem to know the isPrototypeOf method.

You can probably achieve the check with e.g.

var a = [];
a.__proto__ == Array.prototype

at least if in Netscape's server-side JavaScript the __proto__ property
is exposed the same way it is in Netscape's client-side JavaScript.

Docs are here:
<http://web.archive.org/web/20031202201701/devedge.netscape.com/central/javascript/>
but although isPrototypeOf is implemented in JavaScript 1.5 it doesn't
seem to be in the 1.5 core docs.

--

Martin Honnen
http://JavaScript.FAQTs.com/