It may seem like a strange way to spec the language, but I'm not sure what would have been better. It wouldn't make sense for sort to have to run through the array checking types before it starts, or for it to dynamically change what kind of comparison it does depending on the types of each pair of elements being compared.
arr1.sort( Array.NUMERICAL | Array.DESCENDING )
arr2.sort( Array.CASE_INSENSITIVE )
E.g.:
[1,3,NaN,2,5].sort( (a,b) => a<b ? -1 : 1 )
// Chrome: [ NaN, 1, 2, 3, 5 ]
// Firefox: [ 2, 5, NaN, 1, 3 ]In (almost) every other language ever the following is true. In Javascript it is false.
[2] < [11]
[[2], [11]].sort() // Javascript: [ [11], [2] ]
As for the actual behavior of ([2] < [11]), the issue there is that "Array" is not a type in JS, arrays are just objects that happen to have properties called "0" and "1" and so on. Hence operators don't have any special cases for arrays, so getting comparisons to work like you had hoped would mean the comparison operator would need weird special rules where, whenever it's passed two objects it checks if they both have properties called "0", and if so do one thing, if not do something else, etc.