如何检查元素是否存在于数组对象中

Question

I'm trying to check if an array within an object contains an element userAnswer or not. Is there a good way to do this using es6. I've tried a few however, I can't seem to get it to work properly. Most of my attempts return an error. Any help would be appreciated.

Last Attempt

conductedExam.questions.some(question => question.userAnswer.includes(Object))

Data

{
  _id: '1',
  questions: [
    { name: '1', userAnswer: 'one' },
    { name: '2', userAnswer: 'two' },
    { name: '2' }
  ]
};

Answer 1

Use hasOwnProperty :

 const conductedExam = { _id: '1', questions: [ { name: '1', userAnswer: 'one' }, { name: '2', userAnswer: 'two' }, { name: '2' } ] }; console.log(conductedExam.questions.some(e => !e.hasOwnProperty("userAnswer"))); 

Answer 2

Using hasOwnProperty might work.

conductedExam.questions.some(question => question.hasOwnProperty('userAnswer')) returns true