jquery how to replace live text?

i've got some text that is being loaded into a <span> from a json file.

the json file has some fields that come as null and i would like to replace them with something else.

i've een trying this :

var e = $('span.black').text();
e.replace(/\null/g, "test");

but it doesn't seem to work.

Another thing is that i try to replace the text immediately after i load the json file开发者_开发问答.

thanks

I would suggest you change the text right after the JSON is loaded like this:

if (!data.someKey) {
   data.someKey = "some default text";
}

$('span.black').text(data.someKey);

or, if you really need to replace the value after it was added to the span:

var elem = $('span.black');
elem.text(elem.text().replace(/null/g, "some default text"));

Given this HTML:

<span id="target">Old Content</span>

The following JQuery code will change the content:

$('#target').html("New Content");

Example @ jsfiddle.net