underscore.js - Determine if all values in an array of arrays match

Question

I have an array of arrays, which looks something like this:

[["Some string", "Some other string"],["Some third string", "some fourth string"]]

I think I can use the _.all method in Underscore to determine if all of the arrays match 100% (that is all of their values match), but I'm not sure how to write the required iterator to run the check.

Anyone have an idea?

Answer 1

Why not intersection? (if you really want to use some Underscore functions for this) http://underscorejs.org/#intersection

If the arrays are of the same length, and the length of the intersection equals to the length of the arrays, then they all contain the same values.

Answer 2

My preference:

_.isEqual(_.sortBy(first), _.sortBy(second))

And if order matters:

_(first).isEqual(second)

Answer 3

Try this guy (order-independent):

function allArraysAlike(arrays) {
  return _.all(arrays, function(array) {
    return array.length == arrays[0].length && _.difference(array, arrays[0]).length == 0;
  });
}

This is assuming you want all of the arrays to contain all the same elements in the same order as one another (so for your example input the function should return false).