How do I count all objects in the current schema?

SQL*Plus: Release 10.2.0.1.0 - Production on Wed Apr 1 09:58:46 2009

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Connected to:
Oracle 12g Enterprise Edition Release 12.1.0.1.0 - 64bit Production
With the Expensive option

SQL> select
  2    user,
  3    count(*)
  4  from
  5    user_objects
  6  where
  7    status='INVALID';
  user,
  *
ERROR at line 2:
ORA-00937: not a single-group group function

Disconnected from Oracle 12g Enterprise Edition Release 12.1.0.1.0 - 64bit Production
With the Expensive option

It does not seem to work … What’s wrong?