Get the value of checked checkbox?

问题

So I've got code that looks like this:

<input class="messageCheckbox" type="checkbox" value="3" name="mailId[]">
<input class="messageCheckbox" type="checkbox" value="1" name="mailId[]">

I just need Javascript to get the value of whatever checkbox is currently checked.

EDIT: To add, there will only be ONE checked box.

回答1:

For modern browsers:

var checkedValue = document.querySelector('.messageCheckbox:checked').value;

By using jQuery:

var checkedValue = $('.messageCheckbox:checked').val();

Pure javascript without jQuery:

var checkedValue = null; 
var inputElements = document.getElementsByClassName('messageCheckbox');
for(var i=0; inputElements[i]; ++i){
      if(inputElements[i].checked){
           checkedValue = inputElements[i].value;
           break;
      }
}

回答2:

None of the above worked for me but simply use this:

document.querySelector('.messageCheckbox').checked;

Happy coding.

回答3:

I am using this in my code.Try this

var x=$("#checkbox").is(":checked");

If the checkbox is checked x will be true otherwise it will be false.

回答4:

in plain javascript:

function test() {
    var cboxes = document.getElementsByName('mailId[]');
    var len = cboxes.length;
    for (var i=0; i<len; i++) {
        alert(i + (cboxes[i].checked?' checked ':' unchecked ') + cboxes[i].value);
    }
}

function selectOnlyOne(current_clicked) {
    var cboxes = document.getElementsByName('mailId[]');
    var len = cboxes.length;
    for (var i=0; i<len; i++) {
        cboxes[i].checked = (cboxes[i] == current);
    }
}

回答5:

$(document).ready(function() {
  var ckbox = $("input[name='ips']");
  var chkId = '';
  $('input').on('click', function() {
    
    if (ckbox.is(':checked')) {
      $("input[name='ips']:checked").each ( function() {
   			chkId = $(this).val() + ",";
        chkId = chkId.slice(0, -1);
 	  });
       
       alert ( $(this).val() ); // return all values of checkboxes checked
       alert(chkId); // return value of checkbox checked
    }     
  });
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
<input type="checkbox" name="ips" value="12520">
<input type="checkbox" name="ips" value="12521">
<input type="checkbox" name="ips" value="12522">

回答6:

This does not directly answer the question, but may help future visitors.

If you want to have a variable always be the current state of the checkbox (rather than having to keep checking its state), you can modify the onchange event to set that variable.

This can be done in the HTML:

<input class='messageCheckbox' type='checkbox' onchange='some_var=this.checked;'>

or with JavaScript:

cb = document.getElementsByClassName('messageCheckbox')[0]
cb.addEventListener('change', function(){some_var = this.checked})

回答7:

Use this:

alert($(".messageCheckbox").is(":checked").val())

This assumes the checkboxes to check have the class "messageCheckbox", otherwise you would have to do a check if the input is the checkbox type, etc.

回答8:

<input class="messageCheckbox" type="checkbox" onchange="getValue(this.value)" value="3" name="mailId[]">

<input class="messageCheckbox" type="checkbox" onchange="getValue(this.value)" value="1" name="mailId[]">

function getValue(value){
    alert(value);
}

回答9:

If you're using Semantic UI React, data is passed as the second parameter to the onChange event.

You can therefore access the checked property as follows:

<Checkbox label="Conference" onChange={(e, d) => console.log(d.checked)} />

回答10:

In my project, I usually use this snippets:

var type[];
$("input[name='messageCheckbox']:checked").each(function (i) {
                type[i] = $(this).val();
            });

And it work well. Best regard.

来源：https://stackoverflow.com/questions/11599666/get-the-value-of-checked-checkbox

标签

javascript

checkbox