Ajax to php call isn't successful - php

Question

I'm trying to test an ajax call on post by doing the following just for testing purposes, but for some reason the call is never successful. I've been searching around and there isn't much that I could find that would explain why this isn't working.
$.ajax({
type: "POST",
url: "file.php",
success: function(data) {
if(data == 'true'){
alert("success!");
}
},
error: function(data) {
alert("Error!");
}});
file.php contains the following:
<?php
return true;
?>
Can someone please point me in the right direction. I realize that this may seem simple but I am stumped. Thank.

Answer 1

return true will make the script exit. You need:
echo 'true';

Answer 2

Firstly check your paths. Is file.php residing in the same folder as the file that your javascript is contained in?
If your path is incorrect, you will get a 404 error printed to your javascript console if you are using chrome.
Also you should change your php to:
<?php
echo 'true';
Once your path is correct and your php is amended you should be good to go.

Answer 3

Have you tried by accessing to the file directly and see if it outputs something?
return true shouldn't be use in that case (or any other, it's better to use exit or die), everything get by a AJAX call is hypertext generated by server side, you should use (as they pointed you before echo 'true';)
You could also try a traditional AJAX call XMLHttpRequest (without JQuery) if problem persists, and then check if there is any problem between the request and server..
EDIT: also, do not check by comparison, just make an alert to 'data' to see what it gets.

Answer 4

In addition to the echo 'true' suggestion, you can also try to alert the actual data that's returned to ajax. That way you can see if you have the proper value/type for your if statement.
success: function(data) {
alert(data);
}

Answer 5

try this, the new ajax syntax
$.ajax({ type: "POST", url: "file.php" }).done(function(resp){
alert(resp);
});

Answer 6

Here is correct way:
$.ajax({
type : "POST",
url : "file.php",
success : function (data) {
/* first thing, check your response length. If you are matching string
if you are using echo 'true'; then it will return 6 length,
Because '' or "" also considering as response. Always use trim function
before using string match.
*/
alert(data.length);
// trim white space from response
if ($.trim(data) == 'true') {
// now it's working :)
alert("success!");
}
},
error : function (data) {
alert("Error!");
}
});
PHP Code:
<?php
echo 'true';
// Not return true, Because ajax return visible things.
// if you will try to echo true; then it will convert client side as '1'
// then you have to match data == 1
?>