How do I remove a specific element from an Array?

Question

data = {
      "test": {
    
    "questions": [
        {
            "option1Id": "1001",
            "option2Id": "1002",
            "tags": [],
            "_id": "60e57c069107a038085ae3a1",
            "question": "what is the atomic number of oxygen?",
            "option1": "5",
            "option2": "6",
            "option3": "7",
            "option4": "8",
            "explanation": "The atomic number of oxygen is 8 and the mass number of oxygen is 16.",
            "level": "Easy",
            "option3Id": "1003",
            "option4Id": "1004"
                }]
              }
    }

I want to achieve something like this:

[{ option1: '5', option1Id: '1001'}, 
 {option2: '6', option2Id: '1002'}, 
 {option3: '7', option3Id: '1003'}, 
 {option4: '8', option4Id: '1004'}]

Right Now, I'm trying to separate option1Id, option2Id, option3Id, and option4Id from option1, option2, option3, option4.

This is what I've done until now:

data = {
  test: {
    questions: [
      {
        option1Id: '1001',
        option2Id: '1002',
        tags: [],
        _id: '60e57c069107a038085ae3a1',
        question: 'what is the atomic number of oxygen?',
        option1: '5',
        option2: '6',
        option3: '7',
        option4: '8',
        explanation:
          'The atomic number of oxygen is 8 and the mass number of oxygen is 16.',
        level: 'Easy',
        option3Id: '1003',
        option4Id: '1004',
      },
    ],
  },
};

options = [];
// console.log(Object.keys(data.test.questions[0]))
entries = Object.entries(data.test.questions[0]);
for (let i = 0; i < entries.length; i++) {
  // options.push(entries[i][0].filter(e => (e.length = 6) && (e.includes('option'))));
  if (entries[i][0].includes('option')) options.push(entries[i]);
}
console.log(options, 'First Options');

for (let i = 0; i < options.length; i++) {
  if (options[i][0].includes('Id')) options.splice(options[i], 1);
   }

console.log(options, 'Second options');

As you can see, I can't seem to get rid of option3Id and option4Id. Is there any way I can do that? And after that how do I convert it into my desired form?

LeeLenalee · Accepted Answer · 2021-07-07 13:07:49Z

2

You could use a regex test instead of checking if the name has option in it:

data = {
  test: {
    questions: [{
      option1Id: '1001',
      option2Id: '1002',
      tags: [],
      _id: '60e57c069107a038085ae3a1',
      question: 'what is the atomic number of oxygen?',
      option1: '5',
      option2: '6',
      option3: '7',
      option4: '8',
      explanation: 'The atomic number of oxygen is 8 and the mass number of oxygen is 16.',
      level: 'Easy',
      option3Id: '1003',
      option4Id: '1004',
    }, ],
  },
};

options = [];
let reg = /option\d$/
entries = Object.entries(data.test.questions[0]);

for (let i = 0; i < entries.length; i++) {

  if (reg.test(entries[i][0])) {
    let tmpObj = {};
    let idVersion = entries.find(el => el[0] === (entries[i][0] + 'Id'));
    
    tmpObj[entries[i][0]] = entries[i][1];
    tmpObj[idVersion[0]] = idVersion[1];
    
    options.push(tmpObj);
  }
}
console.log(options, 'First Options');

edited Jul 7, 2021 at 13:07

answered Jul 7, 2021 at 11:51

LeeLenalee

31.9k7 gold badges62 silver badges81 bronze badges

Sign up to request clarification or add additional context in comments.

6 Comments

ikhvjs Over a year ago

I think you almost finish it. It would be better to output an expected result OP wants.

LeeLenalee Over a year ago

@ikhvjs thanks, read his question not totally, thanks for pointing it out. Updated answer

ab1004 Over a year ago

Thank you so much for the solution! Could you please also explain to me why the splice() method doesn't work as I was expecting it to be? I mean why do option3Id and option4Id remain while option1Id and option2Id don't?

ab1004 Over a year ago

Also, could you explain to me what if (reg.test(entries[i][0])) does exactly?

LeeLenalee Over a year ago

your object.entries returns arrays with first element the key of the obj and second el the val, I take the key from it and test if it passes the regex so I know its a key in the value of option+number developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/…

|

Collectives™ on Stack Overflow

How do I remove a specific element from an Array?

1 Answer 1

6 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

6 Comments

Your Answer

Sign up or log in

Post as a guest

Related