javascript surprising array comparison

Question

I\'m trying to compare two arrays in javascript.

What I\'d like is:

a < b ⇔ ∃ i ≥ 0 s.t. a[i] < b[i] and ∀ 0 ≤ j

Answer 1

There's no such thing as JavaScript array comparison in any form similar to what you describe.

What's happening in all cases is that your arrays are being converted first to strings by joining their contents together. Thus, the string "-2" is not less than the string "-1", because the character "2" comes after "1" in the character set. Similarly, "-1,1" is less than "0,0" because the "-" character comes before the digits.

You can see for yourself that in all cases your comparisons:

array1 < array2

get exactly the same results as:

("" + array1) < ("" + array2)

or:

array1.join(",") < array2.join(",")