Dennis Huang wrote:
>
> Hi:
>
> I have a piece of code look like this:
>
> <%! String str=""; %>
> <% for (int i=1; i < 10; i++) { str = i +"<br>"+str; } %>
> Before <B>JSP</B> Output <P>
> <%= str %>
> <P> After <B>JSP</B> Output
>
> This works. The strange thing is each time I click on the Refresh, <%=str
> %> outputs more and more repeated values(from 9 to 1). It seems <%! String
> str=""; %> does not work from the second time I click on the Refresh button.
> Do you know why? I am using Tomcat and IE5.
That's because the str variable you declare with the JSP declaration
element (<%! ... %>) ends up as an instance variable in the generated
servlet. An instance variable keeps its value between requests, so on the
second request you just add to it.
In general I advice not to use the JSP declaration for variables, since
besides the effect you have seen it also causes multi-threading issues.
If you declare the variable in a scriptlet element instead, it will work
as you expected:
<% String str=""; %>
Note that the only difference is the lack of an exclamation point (!) in
the scriptlet.
Hans
--
Hans Bergsten [EMAIL PROTECTED]
Gefion Software http://www.gefionsoftware.com
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