用ajax检索发布数据

I'm trying to send the value itest via ajax to myfile.php but $_POST['itest']; is not retrieving any data.

the html :

   <form name=test>
   <input name=itest>
   <button>Send</button>
   </form>

the js :

$(document).ready(function() {
  $("form[name='test']").submit(function(e) {
    e.preventDefault();

    var itest = $("input[name=itest]").val();
    $.ajax({
            type:'POST',
            url:'myfile.php',
            data:itest
    });
  });
});

myfile.php

<?php

echo $_POST['itest'];
/* no data on $_POST['itest']; !!! why ? */
?>

Tiny tweak needed ! help !

The problem is, your data param is wrong. You need to send an application/x-www-form-urlencoded string (eg a=1&b=2) or an object literal, eg {a: 1, b: 2}. You are sending a single string value.

Try this instead

var formData = $(this).serialize();
$.post('myfile.php', formData);

And make your button a submit type

<button type="submit">Send</button>

Update

I'd even go so far as to make your JS much more portable

<form action="myfile.php" method="post" id="test">
    <input name="itest">
    <button type="submit">Send</button>
</form>

and the JS

$('#test').on('submit', function(e) {
    e.preventDefault();
    $.post(this.action, $(this).serialize());
});

You are not sending the post data as an object.

The data parameter needs to be an object. You are only passing a single value.

jQuery.ajax states:

data Type: PlainObject or String Data to be sent to the server. It is converted to a query string, if not already a string. It's appended to the url for GET-requests. See processData option to prevent this automatic processing. Object must be Key/Value pairs. If value is an Array, jQuery serializes multiple values with same key based on the value of the traditional setting (described below).

You need to replace itest with a object.

var itest = $("input[name=itest]").val();
$.ajax({
        type:'POST',
        url:'myfile.php',
        data: {'itest' : itest}
});

If we intend to POST all values in the form, which we generally what to do, we can improve on the previous code, by replacing an awkward object literal with some jQuery $(this).serializeArray() . $(this) refers to the form and serializeArray() creates a JavaScript array of objects, ready to be consumed by jQuery.ajax.

jsfiddle

$(document).ready(function () {
    $("form[name='test']").submit(function (e) {
        e.preventDefault();
        // This line added intentionally to show the data/data format used
        console.log(JSON.stringify($(this).serializeArray()));


        $.ajax({
            type: 'POST',
            url: 'myfile.php',
            data: $(this).serializeArray()
        });
    });
});

 $(document).ready(function() {
      $("form[name='test']").submit(function(e) {
        e.preventDefault();

        var itest = {'itest' : $("input[name=itest]").val()};
        $.ajax({
                type:'POST',
                url:'myfile.php',
                data:itest
        });
      });
    });