简单的Jquery POST调用不起作用

Question

I got a simple POST call to a PHP file on my website. For some reason it's not working though. The console.log shows"undefined"

function check() {
  var url = "../API/keychecker.php";
  var spullen = $("keyval").val;
  $.ajax({
    type: "POST",
    url: url,
    data: {
      key: spullen
    },
    success: function(data) {
      console.log(data);
    }
  })
}

Here is the PHP file:

<?php
  echo json_encode($_POST['key']);
?>

Answer 1

Your keyval call doesn't specify the type of element identifier. jQuery won't find the element you're looking for as you currently have it.

You must specify:

For classes:

$( ".keyval" ).val();

For ID

$( "#keyval" ).val();

For input name

$( "input[name=keyval]" ).val();

That should attach the value to the POST request.