Array.apply(null, Array(9)) vs new Array(9)

Asked Dec 18 '15 at 05:33

Active Dec 18 '15 at 06:05

Viewed 706 times

I'm trying to create an array of zeroes and I can get the desired result by using:

Array.apply(null, Array(9)).map(Number.prototype.valueOf, 0)

but I get the wrong thing if I use:

new Array(9).map(Number.prototype.valueOf, 0)

And for that matter any attempt to map on the result of new Array(len) fails to return the expected array on a mapping. Can someone help me understand why this is the case?

edited Dec 18 '15 at 05:55

RobG

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asked Dec 18 '15 at 05:33

mb_s88

Array.apply(null, Array(9)) vs new Array(9)

0 Answers0