Uncheck checkbox when certain values from drop down is chosen

问题

I need to uncheck my checkbox when i choose a certain value from my drop down list or when the user does not select any value from the drop down list. Im using Jquery at the moment. This is the code that im using right now but it won't work.

Script

<script src="js/jquery-1.8.3.js"></script>
<script>
function sdp4(str) {
       if (  
   $('#drop1').val()!= '' 
|| $('#drop1').val()== "In Process"
|| $('#drop1').val()== "KIV" )

{$('#checkbox1').prop('checked', false);} 
else 
{$('#checkbox1').prop('checked', true);}
</script>

HTML

<select class="form-dropdown"  id="drop1" name="drop1" onchange="sdp4">
        <option value=""> </option>
        <option value="In Process"> In Process </option>
        <option value="KIV"> KIV </option>
        <option value="Completed"> Completed </option>
        </select>  
<input type="checkbox" checked="checked" id="checkbox1" name="checkbox1" />

回答1:

Assuming the only time you want the check box checked is when completed is selected:

 $("#drop1").on('change', function () {
    var val = $(this).val();
    if (val === " " || val === "In Process" || val === "KIV") {
        $('#checkbox1').prop('checked', false);
        return;
    }
    $('#checkbox1').prop('checked', true);
});

and html:

<select class="form-dropdown" id="drop1" name="drop1">
    <option value=" "></option>
    <option value="In Process">In Process</option>
    <option value="KIV">KIV</option>
    <option value="Completed">Completed</option>
</select>
<input type="checkbox"  id="checkbox1" name="checkbox1"/>

Here is a FIDDLE

回答2:

You need to actually bind the call to sdp4 to something:

$("#drop1").on('change', sdp4);

At that point it would also be redundant to use #drop1 in the selectors when you could use this.

回答3:

Try this: http://jsfiddle.net/7cqDB/

function sdp4(str) {
  if (str == '' || str == "In Process" || str == "KIV") {
      $('#checkbox1').prop('checked', false);
  } else {
      $('#checkbox1').prop('checked', true);
  }
}

$(function () {
   $('select').on('change', function () {
       var str = $(this).val();
       sdp4(str);
   });
});

来源：https://stackoverflow.com/questions/14699237/uncheck-checkbox-when-certain-values-from-drop-down-is-chosen

标签

javascript

jquery

checkbox

html-select