如何在javascript中将变量传递给href？

Question

How to pass this variable value here? Below code is not working. And all other discussions on Stackoverflow are unclear.

<script type="text/javascript">
        function check()
        {
            var dist = document.getElementById('value');
            if (dist!=""){
                window.location.href="district.php?dist="+dist;
            }
            else
               alert('Oops.!!');
        }
</script>

And my HTML code is:

<select id="value" name="dist" onchange="return check()">

Answer 1

You have to fetch field value using .value as you are passing whole object to the URL as document.getElementbyId('value') returns whole field object.

var dist = document.getElementById('value').value;

So your function should be like this

function check() {
    var dist = document.getElementById('value').value; // change here
    if (dist != "") {
        window.location.href = "district.php?dist=" + dist;
    } else
        alert('Oops.!!');
}

Answer 2

You have fetch value of the field, Currently you are using DOM object

Use

 var dist = document.getElementById('value').value;

OR

Use

 if (dist.value!=""){
     window.location.href="district.php?dist="+dist.value;

instead of

if (dist!=""){
     window.location.href="district.php?dist="+dist;

Answer 3

Try this:

function check() {
    var dist = document.getElementById('value').value;

    if (dist) {
        window.location.href = "district.php?dist=" + dist;
    } else {
        alert('Oops.!!');
    }
}

Answer 4

Try this:

var dist = document.getElementById('value').value;
if (dist != "") {
 window.location.href="district.php?dist="+dist;
}

Answer 5

You have to make some correction in your function..

function check()
    {
        var dist = document.getElementById('value').value;  //for input text value
       if (dist!==""){  //  for comparision
           window.location.href="district.php?dist="+dist;
       }
       else
           alert('Oops.!!');
    }

Answer 6

I use a very different approach to this. I set browser cookies in the client that expire a second after I set window.location.href .

This is way more secure than embedding your parameters in the URL.

The server receives the parameters as cookies, and the browser deletes the cookies right after they are sent.

const expires = new Date(Date.now() + 1000).toUTCString()
document.cookie = `oauth-username=user123; expires=${expires}`
window.location.href = `https:foo.com/oauth/google/link`