David-Sarah Hopwood wrote:
> Mark S. Miller wrote:
> > function isArrayLike(obj) {
> > var len;
> > return !!(obj &&
> > typeof obj === 'object' &&
> > 'length' in obj &&
> > !({}).propertyIsEnumerable.call(obj, 'length') &&
> > (len = obj.length) >>> 0 === len);
> > }
>
> If you want to avoid side effects:
>
> function isArrayLike(obj) {
> if (!obj || typeof obj !== 'object') return false;
> var desc = Object.getOwnPropertyDescriptor(obj, 'length');
> if (desc) {
> var len = desc.value;
> return !desc.enumerable && (len === undefined || len >>>
> 0 === len);
> }
> }
An advantage with Mark's code is that it doesn't rely
on ES5 API. I think it's good to establish a standard
for array-likeness that can be matched by ES3 code as
well.
Best regards
Mike
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