http://www.freecodecamp.com/minsooshin 's solution for Bonfire: Everything Be True

bonfire-everything-be-true.js

// Bonfire: Everything Be True
// Author: @minsooshin
// Challenge: http://www.freecodecamp.com/challenges/bonfire-everything-be-true
// Learn to Code at Free Code Camp (www.freecodecamp.com)

function every(collection, pre) {
  // Is everyone being true?
  var falsyArr = collection.filter(function(val) {
    return !(val[pre]);
  });
  if (falsyArr.length) return false;
  else return true;
}

every([{"user": "Tinky-Winky"}, {"user": "Dipsy", "sex": "male"}, {"user": "Laa-Laa", "sex": "female"}, {"user": "Po", "sex": "female"}], "sex");
//=> false