CODEWITHSUNDEEP
phpjavascripthtmlajaxvariables
fosho
fosho

Reputation: 1676

Ajax sending to variable to php undefined index

I would like to display the variable num in the php page.

The error i am getting is as follows:

Notice: Undefined index: num in C:\xampp\htdocs\javas.php on line 4

PHP:

<?php 
$lol = $_POST['num'];
echo "$lol " ;
?>

HTML/Javascript:

<html>
<head>
<script language="JavaScript" type="text/javascript">
function ajax_post(){
// Create our XMLHttpRequest object
var hr = new XMLHttpRequest();
// Create some variables we need to send to our PHP file
var url = "javas.php";
var num = "lol";

hr.open("POST", url, true);
// Set content type header information for sending url encoded variables in the request
hr.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
// Access the onreadystatechange event for the XMLHttpRequest object
hr.onreadystatechange = function() {
    if(hr.readyState == 4 && hr.status == 200) {
        var return_data = hr.responseText;
        document.getElementById("status").innerHTML = return_data;
    }
}
// Send the data to PHP now... and wait for response to update the status div
hr.send(num); // Actually execute the request
document.getElementById("status").innerHTML = "processing...";
}
</script>
</head>
<body>
<h2>Ajax Post to PHP and Get Return Data</h2>

<input name="myBtn" type="submit" value="increment" onClick="javascript:ajax_post();">
<br /><br />
<div id="status"></div>
</body>
</html>

Upvotes: 0

Views: 2170

Answers (2)

Brian Driscoll
Brian Driscoll

Reputation: 19635

One part of the issue here is that the parameter that you're posting is not properly serialized. The parameter string for a POST is similar to the query string for a GET request:

var1=foo&var2=bar

As it stands right now you're just sending a raw piece of data over (the value assigned to the variable num.

Upvotes: 0

James
James

Reputation: 22247

You have to send name/value pairs

hr.send("num=" + num);

Upvotes: 3

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