I'm trying to get the field values and field meta data ie., field properties,

Using the following script I'm able to find the field type and field properties. Now im trying to check if there is any null value in the a particular field, so that I can replace the field value with the default values based on the field type.

How can I read the field values without using the input fields ie.,hard coding (ie., to use some inbuilt functions as of how we get the meta data)following is the snip of code that i used to get the field properties