title: ABAP create object
body: <p>Below is a code snippet that is creating object.</p>
  
  <pre><code>Form userexit_save_document_prepare.
    data: /bks/exitmanager type ref to /bks/exit_manager.
    create object /bks/exitmanager
           exporting main_prog = 'SAPMV45A'
                     exit_form = 'USEREXIT_SAVE_DOCUMENT_PREPARE'.
    include /bks/exitman.
  ENDFORM.
  </code></pre>
  
  <p>I got this from the documentation </p>
  
  <blockquote>
    <p>For performance reasons, the parameters "main_prog" and "exit_form" should be filled, in the case of userexits, which are performed very often like "user_field_modification" in "SAPMV45A" which is called for every single screen-field.</p>
  </blockquote>
  
  <p>1) What happened exactly behind when create object /bks/exitmanager is called? memory allocated for the object etc?</p>
  
  <p>2) Why for performance reasons the exporting parameters of create object needs to be filled?</p>