How to programatically add a pseudo field to views and display the field value based on value of other field? I need to add a field to view and display the value of that field depending on the value of other fields already present. 

The pseudo field i need to add is not connected with any database table.
In addition to the preprocess hook approach noted in the comments, you may want to use:


Computed Field Module https://www.drupal.org/project/computed_field
Views PHP Module https://www.drupal.org/project/views_php