how to use status codes 200, 404, 300 ( how jquery done and fail work internally) [closed]

Answer 1

In addition to what @dfsq wrote, you can handle specific status codes:

$.ajax({
  statusCode: {
    404: function() {
      alert( "page not found" );
    }
  }
});

or with deferred:

$.ajax({
    url: "update.php",
    type: "POST",
    data: customObj
})
.fail(function( jqXHR, textStatus, errorThrown) {
    if (jqXHR.status == 403) {
        alert( "forbidden" );
    }
});

or:

$.ajax({
    url: "update.php",
    type: "POST",
})
.statusCode({
    401: function() { alert( 'Unauthorized' ); },
    200: function() { alert( 'OK!'); }
});