Everything be true

index.js

/*
Check if the predicate (second argument) is truthy on all elements of a collection (first argument).

Remember, you can access object properties through either dot notation or [] notation.
*/

function truthCheck(collection, pre) {
  return collection.every(function(key) {
    return key[pre];
  });
}
truthCheck(
  [
    { user: 'Tinky-Winky', sex: 'male' },
    { user: 'Dipsy', sex: 'male' },
    { user: 'Laa-Laa', sex: 'female' },
    { user: 'Po', sex: 'female' },
  ],
  'sex'
);

/*
Test your code here
truthCheck([{"user": "Tinky-Winky", "sex": "male"}, {"user": "Dipsy", "sex": "male"}, {"user": "Laa-Laa", "sex": "female"}, {"user": "Po", "sex": "female"}], "sex") should return true.
truthCheck([{"user": "Tinky-Winky", "sex": "male"}, {"user": "Dipsy"}, {"user": "Laa-Laa", "sex": "female"}, {"user": "Po", "sex": "female"}], "sex") should return false.
truthCheck([{"user": "Tinky-Winky", "sex": "male", "age": 0}, {"user": "Dipsy", "sex": "male", "age": 3}, {"user": "Laa-Laa", "sex": "female", "age": 5}, {"user": "Po", "sex": "female", "age": 4}], "age") should return false.
truthCheck([{"name": "Pete", "onBoat": true}, {"name": "Repeat", "onBoat": true}, {"name": "FastFoward", "onBoat": null}], "onBoat") should return false
truthCheck([{"name": "Pete", "onBoat": true}, {"name": "Repeat", "onBoat": true, "alias": "Repete"}, {"name": "FastFoward", "onBoat": true}], "onBoat") should return true
truthCheck([{"single": "yes"}], "single") should return true
truthCheck([{"single": ""}, {"single": "double"}], "single") should return false
truthCheck([{"single": "double"}, {"single": undefined}], "single") should return false
truthCheck([{"single": "double"}, {"single": NaN}], "single") should return false
*/