jQuery Dynamic Function and Variable

Question

I am trying to create a function that handles the 'keyup' event for several input fields and passes the input value to a php script. Here's the code I have so far

$(document).ready(function () {
 $("#email").keyup(function () {
 val = $("input#email").val();
 what = 'email';
 aFunction(val, what);
 });
});
function aFunction(val, what) {
 var dataString = what + '=' + val;
 var error = "email_check";
 $.post("key.php", dataString, function (data) {
 //if (data.[error] == 'invalid'){
 if (data.email_check == 'invalid') {
 $("#ppp").html('error');
 } else {
 $("#ppp").html('good to go');
 }
 }, "json");
 //return false; 
}

When I uncomment

//if (data.[error] == 'invalid'){

and comment out

if (data.email_check == 'invalid'){

My the script doesnt execute and js file doesn't load into the firebug script console - I assume means there's an error because when I undo that and refresh I can view it. I've tried added single and double quotes to the variable. Also, it would be helpful if there was a way to see what the is error is, but I don't know how to do that.

• Joe Riggs: Mods - why do you keep editing my posts? Am I doing something wrong, I cant see any changes?
• Crescent Fresh: I added the javascript tag to the question, as I saw the problem was just a syntax error. Is that ok?
• Joe Riggs: No problem at all, I just thought I was making more work for you guys :)

Answer 1

Your primary problem here is that you should use either dot notation ("data.error") or array notation ("data['error']") but not both ("data.['error']").

• kangax: It's actually called "bracket notation" ;)
• Joe Riggs: ps - what's my secondary problem?

Answer 2

Javascript does not support braces in identifiers.

If the key is actually just error, you can write if (data.error == 'invalid').
If it is [error], you'll need to write if (data['[error]'] == 'invalid)`.

To see syntax errors, go to Firebug's Console tab.

• Joe Riggs: +1 thanks for the heads up on console tab. I kept googling for 'validate jquery code' and it came back with links for the validator plugin