jQuery post() with serialize and extra data

An alternative solution, in case you are needing to do this on an ajax file upload:

var data = new FormData( $('#form')[0] ).append( 'name' , value );

OR even simpler.

$('form').on('submit',function(e){

    e.preventDefault();
    var data = new FormData( this ).append('name', value );

    // ... your ajax code here ...

    return false;

});

When you want to add a javascript object to the form data, you can use the following code

var data = {name1: 'value1', name2: 'value2'};
var postData = $('#my-form').serializeArray();
for (var key in data) {
    if (data.hasOwnProperty(key)) {
        postData.push({name:key, value:data[key]});
    }
}
$.post(url, postData, function(){});

Or if you add the method serializeObject(), you can do the following

var data = {name1: 'value1', name2: 'value2'};
var postData = $('#my-form').serializeObject();
$.extend(postData, data);
$.post(url, postData, function(){});

Try $.param

$.post("page.php",( $('#myForm').serialize()+'&'+$.param({ 'wordlist': wordlist })));

You can use serializeArray ^[docs] and add the additional data:

var data = $('#myForm').serializeArray();
data.push({name: 'wordlist', value: wordlist});

$.post("page.php", data);