Everything Be True

所有的东西都是真的！

完善编辑器中的every函数，如果集合(collection)中的所有对象都存在对应的属性(pre)，并且属性(pre)对应的值为真。函数返回ture。反之，返回false

function every(collection, pre) {
  // Is everyone being true?
  var passed=collection.every(function(val){
    return val.hasOwnProperty(pre)&&val[pre];
  });
  return passed;
}

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