Why does httpr.send() always fail?-CodePudding

I had similar code run before but now i've lost it. No matter what I do, it will never run the php code.

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script>
        function kosarica() {
        var vrednost = "Itworks!";
        var httpr=new XMLHttpRequest();
        httpr.open("POST","izpis3.php",true);
        httpr.setRequestHeader("Content-type","aplication/x-www-form-urlencode");
        httpr.onreadystatechange=function(){
            if(httpr.readyState==4 && httpr.status ==200){
                document.getElementById("responce").innerHTML=httpr.responseText;
            }
            httpr.send("vrednost" vrednost);
        }
    }
    </script>
</head>
<body>
    
    <p id="responce">a</p>
    <button onclick="kosarica()">Click me</button>
    
</body>
</html>

PHP Code:

<?php
    echo $_POST['vrednost'];
?>

I know that I can make code for this example all in javascript but I want to run more php code where it access my database.

CodePudding user response：

It does not fail, but it does never happen. You need to move the send() outside the handler.
The content type is wrong.
You need to use an equal sign to make it a variable for PHP.
Please do not use var keyword. Use const for a constant or let for a variable.

function kosarica() {
    const vrednost = "Itworks!";
    const httpr = new XMLHttpRequest();
    httpr.open("POST", "izpis3.php", true);
    httpr.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
    httpr.onreadystatechange = function () {
        if (httpr.readyState === 4 && httpr.status === 200) {
            document.getElementById("responce").innerHTML = httpr.responseText;
        }
    }
    httpr.send("vrednost="   vrednost);
}