In ArcMap the user can choose the field type of "Integer" and input any number and also commas and decimals. In ArcGIS Online you are not able to input anything other than whole numbers with commas (if needed) but you are not able to put in a decimal. This hinders the user by not allowing them to put in specific numbers into the integer field. Instead the user has to choose string text field type and when trying to integrate the online map into another program the field type may need to be integer in order to function properly. This causes problems in the compatibility. If there is something offered in ArcMap then it should be available in ArcGIS Online to allow users to interact with the map without having to send an .mxd back and forth.