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I’m used to python, so
a = [1,2,3]
1 in a # -> True
b = ["1", "2", "3", "x"]
"x" in b # -> True
Why is it that in JavaScript
a = [1,2,3]
1 in a // -> true
b = ["1", "2", "3", "x"]
"x" in b // -> false
and much weirder
"1" in b // -> true
inworks on KEYS of arrays, not values.1 in asucceeds because there is an element #1 in your array, which is actually the2value."1"fails, because there is no1PROPERTY or KEY in your array.Details here: https://developer.mozilla.org/en/JavaScript/Reference/Operators/in