Looking to determine if two elements exist within an array? Seeking a boolean result based on their presence

Question

Looking to determine if two elements exist within an array? Seeking a boolean result based on their presence

Consider the following array of objects:

quesListArray = [
                  {
                    QuestionTypeID : 1,
                    QuestionTypeName : 'Rating'
                  },
                  {
                    QuestionTypeID : 2,
                    QuestionTypeName : 'Yes/No'
                  },
                  {
                    QuestionTypeID : 3,
                    QuestionTypeName : 'Rating - Matrix'
                  },
                  {
                    QuestionTypeID : 4,
                    QuestionTypeName : 'Yes/No - Matrix'
                  }
                ]

I am looking for a way to determine if QuestionTypeID 1 & 3 exist in the array, return true, otherwise false. The same applies to QuestionTypeID 2 & 4. Any other combination should result in false.

Initially attempted using a for loop:

for(let x of this.quesListArray) {
  if(x.QuestionTypeID == 1 && x.QuestionTypeID == 3) {   // realized it's an incorrect condition
     // return true or false
  }
}

Then I tried using includes() method:

this.quesListArray.includes(this.QuesListArray[..])  // Was uncertain how to structure the conditions for both IDs.

Your guidance on resolving this issue would be greatly appreciated. Thank you.

typescript

Answer 1

Answer №1

Utilizing the .find method: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/find

if (
     quesListArray.find(x=>x.QuestionTypeID == 1) && 
     && quesListArray.find(x=>x.QuestionTypeID == 3)
) {
  // It contains both Question Type IDs 1 and 3.
}

Answer 2

Utilizing the .find method: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/find

if (
     quesListArray.find(x=>x.QuestionTypeID == 1) && 
     && quesListArray.find(x=>x.QuestionTypeID == 3)
) {
  // It contains both Question Type IDs 1 and 3.
}

Answer 3

Answer №2

To achieve this, you can use the includes and find methods in the following way:

Let's say you start with pair p1:

let p1 = [1, 3];

Then your first condition to find will be:

let result = quesListArray.filter(q => p1.includes(q.QuestionTypeID)).length == 2;

This code snippet will return a boolean value (true or false) based on whether quesListArray contains two elements with QuestionTypeIDs equal to 1 and 3. If either of these values is missing, the result will be false.

Answer 4

To achieve this, you can use the includes and find methods in the following way:

Let's say you start with pair p1:

let p1 = [1, 3];

Then your first condition to find will be:

let result = quesListArray.filter(q => p1.includes(q.QuestionTypeID)).length == 2;

This code snippet will return a boolean value (true or false) based on whether quesListArray contains two elements with QuestionTypeIDs equal to 1 and 3. If either of these values is missing, the result will be false.

Looking to determine if two elements exist within an array? Seeking a boolean result based on their presence

Answer №1

Answer №2

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