function getRandomWords () {
  let words = getServerData("http://localhost:3000/words").then(
    data => randomWorldExample(data)
  );
  let howManyWords = document.querySelector("#words-to-memorize");
  let randomElement = words[0].words.sort(() => 0.5 - Math.random())
  console.log("random words: ", randomElement.slice(0, howManyWords));
}

This should get ya there. What we are doing is randomly sorting the array then we are slicing the array to the n value.

My working solution finally was the following:

function getRandomWords() {
    let words = getServerData('http://localhost:3000/words').then(data => {
        const wordsToMemorize = document.querySelector('#words-to-memorize');
        document.querySelector("#wordsInput").addEventListener("click", function() {
            let temp = wordsToMemorize.value;
            selectedtombelemek.innerHTML = "";
            for(let i = 0; i < temp; i++) {
            let rander = Math.floor(Math.random() * 3000);
            selectedtombelemek.innerHTML += data[rander] + "</br>";
        }})
    });
}

I just started to practice Javascript and I have a json file with a bunch of words. I want to display as many words as the given user input. If user input is 4 then 4 words will be displayed randomly from the server. I can successfully get the data from te server and display all of them in a table but the logic of displaying random words from the server is a little difficult for the firs try and I would like to get a better understanding how to approach it in my case. The getRandomWords() function is where I was trying to approach something.

words.json

{
"words":
[
"a",
"abandon",
"ability",
"able",
"abortion",
"about",
"above",
"abroad",
"absence",
"absolute",
"absolutely",
"absorb",
"abuse",
"academic"
]
}

snippet from project.js

function getServerData(url) {
  let fetchOptions = {
    method: "GET",
    mode: "cors",
    cache: "no-cache"
  };
  return fetch(url, fetchOptions).then(
    response => response.json(),
    err => console.error(err)
  );
}
document.querySelector("#server-button").addEventListener("click", function() {
  getServerData("http://localhost:3000/words").then(
    data => fillDataTable(data, "wordTable")
  );
});

function getRandomWords() {
  let words = getServerData("http://localhost:3000/words").then(
    data => randomWordExample(data)
  );
  var howManyWords = document.querySelector("#words-to-memorize");
  const randomElement = words[Math.floor(Math.random() * words.length)];
  console.log("random words: ", randomElement);
}

index.html

<div class="row">
    <div class="col-2"></div>
    <div class="col-8">
        <div class="form-group">
            <label for="words-to-memorize">How many words you want to see?</label>
            <input type="text" class="form-control" id="words-to-memorize">
          </div>
          <button id="get-words-button" class="button btn btn-block btn-primary">
            Get the words
          </button>
    </div>
    <div class="col-2"></div>
</div>