如何检查是否有<li>元素具有特定值

Question

can i Check with JS or JQuery whether an list contains a specific Value or not?

My Code:

HTML:

  <ul class="list-group list-group-flush" id="liste">
  </ul>

JavaScript:

<script type="text/javascript">
  document.getElementById('Add').onclick = function() {
    var Nutzer = document.getElementById('Suche').value;
    var Liste = document.getElementById('liste');
    if (! $("li:has(Test)")) {
      var entry = document.createElement('li');
      entry.setAttribute( 'class', 'list-group-item' );
      entry.appendChild(document.createTextNode(Nutzer));
      Liste.appendChild(entry);
    }
}
</script>

I only found Solutions with li:contains but that is not what I want.

Answer 1

Use Array.prototype.some on the list of li elements

 console.log([...$("#liste li")].some(el => $(el).text() === "Test")); console.log([...$("#liste li")].some(el => $(el).text() === "Anything Else"));

 <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script> <ul class="list-group list-group-flush" id="liste"> <li>Test</li> </ul>

Answer 2

You can do it with only vanilla JS actually...

Take a look:

HTML:
  <ul>
      <li>Banana</li>
      <li>Apple</li>
      <li>Test</li>
      <li>Cucumber</li>
      <li>Coconut</li>
  </ul>

JS:
  const li = document.querySelectorAll('ul li');
  for (let i = 0; i < li.length; i++) {
    // it is the same as contains
    if (/Test/g.test(li[i].textContent)) {
        console.log('I am the <li> you want', li[i])
    }
    // it is the same as equal to
    if (li[i].textContent === 'Test') {
        console.log('I am the <li> you want', li[i])
    }

  }

Cheers,