Why Doesn't Copied Array Equal Original Array?

Asked Oct 28 '16 at 17:52

Active Oct 28 '16 at 17:52

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I've been learning more about functional programming and the idea of keeping functions pure. So I experimented with taking an array and making a copy of it with the slice function like so...

var text = ['a', 'b', 'c'],
copy = text.slice(0);

I have two arrays at this point of the same type and with the same values but when I test to see if they're the same...

text === copy; => returns 'false'

Why isn't the copy seen as the same array by Javascript?

asked Oct 28 '16 at 17:52

Reginald Davis

1

Because in JS object equality means that both are the _same_ object. If they have the same content, but are different objects, then they are treated as being different. – VLAZ Oct 28 '16 at 17:53
That's the point, two different arrays are **never** the same, even if they contain the same values – adeneo Oct 28 '16 at 17:53
http://stackoverflow.com/questions/7837456/how-to-compare-arrays-in-javascript – epascarello Oct 28 '16 at 17:54
Ahh...that makes sense! Thanks for helping clear that up! – Reginald Davis Oct 28 '16 at 21:42

Why Doesn't Copied Array Equal Original Array?

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