15.3.4.3 Function.prototype.apply (thisArg, argArray)

Jose Antonio Perez joseanpg at gmail.com
Thu Oct 28 08:41:29 PDT 2010


In ES5-15.4 is clearly defined what is an index and  what conditions must
verify length

"A property name P (in the form of a String value) is an array index if and
only if ToString(ToUint32(P)) is equal to P and ToUint32(P) is not equal to
2^32-1"


"Every Array object has a length property whose value is always a
nonnegative integer less than 2^32"


Also in the construction of an array  with explicit length (15.4.2.2) that
condition is checked with a possible RangeError exception

"If the argument len is a Number and ToUint32(len) is equal to len, then the
length property of the newly constructed object is set to ToUint32(len). If
the argument len is a Number and ToUint32(len) is not equal to len, a
RangeError exception is thrown."


As Asen suggests would be interesting to define explicity the concept of
"Array like object",  demanding the fulfillment of such conditions.

Jose
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