I know that jQuery.each() has created to work with array and objects, but if you expect some AJAX response, maybe you can receive another type of result. A good programmer can check the result by a valid type, but it can be a big problem if you pass a non array/object to jQuery.each. You too receive variable type of results depending of type, and too, throw an error.

Make a check: http://jsfiddle.net/3EGA6/1/

If affect ALL jQuery versions.

Some observations:

• v1.9.1 (stable/edge) and v2.0.0 (stable/edge) are same;
• v1.8.3 and v1.7.2 accepts strings, splitting it to array;
• v1.6.4 causes strange things to undefined or null types;
• All browser have the same results;