Question

If i enter a value in the input box and click the button. i want to check the input values in the drop down if the values exists in the dropdown i want to remove that option elsei want to add the input value in the option.

HTML:

<input type="text" id="inputValue" />
<button id="myBtn" onclick="validate()">Click</button>
<select id="mySelect">
   <option>Apple</option>
   <option>Orange</option>
   <option>Mango</option>
   <option>Lemon</option>
</select>

JS :

function validate() {
   var ipValue = document.getElementById('inputValue').value;
   var select = document.getElementById('mySelect');
   for(i=0;i<select.length;i++) {
      if(select[i] == ipValue) {
         ipValue.removeChild(select[i]);
      }
      else {
         var option = document.createElement('option');
         select.appendChild(option);
         option.innerHTML = ipValue;
      }
   }
}

Answer 1

function validate() {
        var ipValue = document.getElementById('inputValue').value;
        var select = document.getElementById("mySelect");
        var selectOption = select.children;

        for (i = 0; i < select.length; i++) {
            if (selectOption[i].text == ipValue) {
                select.removeChild(selectOption[i]);
                return;
            } 
        }
        var option = document.createElement('option');
        select.appendChild(option);
        option.text = ipValue;

    }

Answer 2

This one should do that for you.

Amongst others, to delete an option value you use select.options.remove(index) and to add select.add(option)

function validate() {
  var ipValue = document.getElementById('inputValue').value;
  var select = document.getElementById('mySelect');
  for(i=0;i<select.options.length;i++) {    
    if(select.options[i].text == ipValue) {
      select.options.remove(i);
      return;
    }
  }
  if(ipValue.trim().length > 0) {
    var option = document.createElement('option');
    option.text = ipValue;
    select.add(option)
  }
}

<input type="text" id="inputValue" />
<button id="myBtn" onclick="validate()">Click</button>
<select id="mySelect">
   <option>Apple</option>
   <option>Orange</option>
   <option>Mango</option>
   <option>Lemon</option>
</select>

Add and Delete the options in the dropdown based on the input values

2 个答案: