title: printing variables in pl/sql
body: <p>I have the following code:</p>
  
  <pre><code>DECLARE
     v_hire_date DATE:='30-Oct-2000';
     v_six_years BOOLEAN;  
  BEGIN
  IF MONTHS_BETWEEN(SYSDATE,v_fecha_contrato)/12 &gt; 6 THEN
        v_six_years:=TRUE;
  ELSE
        v_six_years:=FALSE;
  END IF;
  DBMS_OUTPUT.PUT_LINE('flag '||v_six_years);
  END;
  </code></pre>
  
  <p>I want to print the value of the variable <code>v_six_years</code>, but I am getting the error:</p>
  
  <pre><code>ORA-06550: line 10, column 24:
  PLS-00306: wrong number or types of arguments in call to '||'
  ORA-06550: line 10, column 3
  </code></pre>
  
  <p>How to print the value of the variable <code>v_six_years</code>?</p>