Javascript - avoid duplicated questions into an array

Question

I have this snippet in my class that use chance.js to generate a random number:

this.askQuestions = [];        
this.questions = JSON.parse(this.questionsData);
for(let i = 0; i < 10; i++){
   let n = chance.integer({min: 0, max: this.questions.length - 1});
   this.askQuestions.push({
       questionIndex: n,
       question: this.questions[n].question,
       choices: this.questions[n].possibleAnswers
   });
}

I'm using it to extract random questions from a json file that have 2000+ entries. During the debug I've set the fixed number of 10 iterations bur I'm working to let the user set a number between 1 and 100. I've noticed that sometimes I will have some questions duplicated and I don't want that this can occur. Can anyone suggest me a way to check and eventually replace duplicated entries into the questions array?

Answer 1

You can use unique() method on chance object to get unique integers.

 this.askQuestions = [];
    
    this.questions = JSON.parse(this.questionsData);
    const questionNumbers = chance.unique(chance.integer, 100, {min: 0, max: this.questions.length - 1})

    for(let i = 0; i < 10; i++){
        let n = questionNumbers[i];

        this.askQuestions.push({
            questionIndex: n,
            question: this.questions[n].question,
            choices: this.questions[n].possibleAnswers
        });
    }