Gunakan skrip untuk memilih tiga slaid secara rawak daripada lima slaid dan paparkannya serta sembunyikan dua slaid yang tidak dipilih

Question

Saya mempunyai kod html dan javascript berikut yang mempunyai gelangsar dengan lima slaid Saya perlu memilih tiga daripada lima slaid secara rawak setiap kali halaman dimuatkan dan meminta dua slaid yang tidak dipilih disembunyikan sepenuhnya. Terima kasih kerana memberitahu saya di manakah masalah dengan kod saya?

Saya mencuba kod berikut tetapi kelima-lima slaid dipaparkan setiap kali halaman dimuatkan, tiga daripada slaid secara rawak mempunyai kandungan dan dua kosong. Saya tidak perlu menunjukkan dua slaid kosong itu

const slogans = Array.from(document.querySelectorAll('.slogan'));
const nonEmptySlogans = slogans.filter(slogan => slogan.innerHTML.trim() !== '');

if (nonEmptySlogans.length >= 3) {
  const selectedSlogans = [];

  while (selectedSlogans.length < 3) {
    const randomIndex = Math.floor(Math.random() * nonEmptySlogans.length);
    const randomSlogan = nonEmptySlogans.splice(randomIndex, 1)[0];
    selectedSlogans.push(randomSlogan);
    randomSlogan.style.display = 'block';
  }
}
'use strict'
var testim = document.getElementById("testim"),
  testimDots = Array.prototype.slice.call(document.getElementById("testim-dots").children),
  testimContent = Array.prototype.slice.call(document.getElementById("testim-content").children),
  testimLeftArrow = document.getElementById("left-arrow"),
  testimRightArrow = document.getElementById("right-arrow"),
  testimSpeed = 4500,
  currentSlide = 0,
  currentActive = 0,
  testimTimer,
  touchStartPos,
  touchEndPos,
  touchPosDiff,
  ignoreTouch = 30;;

window.onload = function() {

  // Testim Script
  function playSlide(slide) {
    for (var k = 0; k < testimDots.length; k++) {
      testimContent[k].classList.remove("active");
      testimContent[k].classList.remove("inactive");
      testimDots[k].classList.remove("active");
    }

    if (slide < 0) {
      slide = currentSlide = testimContent.length - 1;
    }

    if (slide > testimContent.length - 1) {
      slide = currentSlide = 0;
    }

    if (currentActive != currentSlide) {
      testimContent[currentActive].classList.add("inactive");
    }
    testimContent[slide].classList.add("active");
    testimDots[slide].classList.add("active");

    currentActive = currentSlide;

    clearTimeout(testimTimer);
    testimTimer = setTimeout(function() {
      playSlide(currentSlide += 1);
    }, testimSpeed)
  }

  testimLeftArrow.addEventListener("click", function() {
    playSlide(currentSlide -= 1);
  })

  testimRightArrow.addEventListener("click", function() {
    playSlide(currentSlide += 1);
  })

  for (var l = 0; l < testimDots.length; l++) {
    testimDots[l].addEventListener("click", function() {
      playSlide(currentSlide = testimDots.indexOf(this));
    })
  }

  playSlide(currentSlide);

  // keyboard shortcuts
  document.addEventListener("keyup", function(e) {
    switch (e.keyCode) {
      case 37:
        testimLeftArrow.click();
        break;

      case 39:
        testimRightArrow.click();
        break;

      case 39:
        testimRightArrow.click();
        break;

      default:
        break;
    }
  })

  testim.addEventListener("touchstart", function(e) {
    touchStartPos = e.changedTouches[0].clientX;
  })

  testim.addEventListener("touchend", function(e) {
    touchEndPos = e.changedTouches[0].clientX;

    touchPosDiff = touchStartPos - touchEndPos;

    console.log(touchPosDiff);
    console.log(touchStartPos);
    console.log(touchEndPos);


    if (touchPosDiff > 0 + ignoreTouch) {
      testimLeftArrow.click();
    } else if (touchPosDiff < 0 - ignoreTouch) {
      testimRightArrow.click();
    } else {
      return;
    }

  })
}

<div class="container">
  <section id="testim" class="testim">
    <div class="testim-cover">
      <div class="wrap">

        <span id="right-arrow" class="arrow right fa fa-chevron-right"></span>
        <span id="left-arrow" class="arrow left fa fa-chevron-left "></span>
        <ul id="testim-dots" class="dots">
          <li class="dot active"></li>
          <!--
                    -->
          <li class="dot"></li>
          <!--
                    -->
          <li class="dot"></li>
          <!--
                    -->
          <li class="dot"></li>
          <!--
                    -->
          <li class="dot"></li>
        </ul>
        <div id="testim-content" class="cont">

          <div class="slogan">
            <p>"How does visual identity design help business/product value grow?"</p>
            <h2>MINE</h2>
          </div>

          <div class="slogan">
            <p>"How can we analyze ourselves, audience, competitors, and market and help business progress/grow?"</p>
            <h2>MINE</h2>
          </div>

          <div class="slogan">
            <p>"How can I differentiate my business from others?"</p>
            <h2>MINE</h2>
          </div>

          <div class="slogan">
            <p>"What is the best and latest business model and plan for me?"</p>
            <h2>MINE</h2>
          </div>

          <div class="slogan">
            <p>"How will innovative targeting be achieved at each stage of business?"</p>
            <h2>MINE</h2>
          </div>

        </div>

      </div>
    </div>
  </section>
</div>

Answer 1

Cuba set ini.

const getRandomNumber = count => Math.floor(Math.random() * count);
const randomNumbers = (len, count) => {
  const numbers = new Set();
  while (numbers.size < len) numbers.add(getRandomNumber(count));
  return [...numbers];
};

const slogans = [...document.querySelectorAll('.slogan')];
const nonEmptySlogans = slogans.filter(slogan => slogan.textContent.trim() !== '');

if (nonEmptySlogans.length >= 3) {
  const showList = randomNumbers(3, nonEmptySlogans); // get 3 of how many found
  slogans.forEach((slogan,i) => slogan.classList.toggle("show",showList.contains(i))
}

Gunakan CSS ini

.slogan { display: none }
.slogan.show { display: block }