Re: [OT] "if" don't work?!?!?
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Chuck,
Caldarale, Charles R wrote:
>> From: Christopher Schultz [mailto:[EMAIL PROTECTED]
>> Subject: Re: [OT] "if" don't work?!?!?
>>
>> String Pippo = "on";
>>
>> if(Pippo == "on")
>>System.err.println("Pippo is on, man!");
>
> Again, that's not what the OP coded; Pippo was retrieved from the
> request, not set to a constant. Changing the context of the if
> statement can certainly changes the result.
Agreed. Your quote, however, was out of context. You only showed the
comparison between a (most likely String) reference type and a literal
string and asserted that it was guaranteed not to work. In that context
(i.e. none), your statement was not true.
- -chris
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RE: [OT] "if" don't work?!?!?
> From: Christopher Schultz [mailto:[EMAIL PROTECTED]
> Subject: Re: [OT] "if" don't work?!?!?
>
> String Pippo = "on";
>
> if(Pippo == "on")
>System.err.println("Pippo is on, man!");
Again, that's not what the OP coded; Pippo was retrieved from the
request, not set to a constant. Changing the context of the if
statement can certainly changes the result.
- Chuck
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Re: [OT] "if" don't work?!?!?
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Chuck,
Caldarale, Charles R wrote:
>> From: Massimiliano PASQUALONI
>> [mailto:[EMAIL PROTECTED]
>> Subject: "if" don't work?!?!?
>>
>>if (Pippo == "on") {
>
> Guaranteed to be false.
Not always:
String Pippo = "on";
if(Pippo == "on")
System.err.println("Pippo is on, man!");
...will print the string ;)
But, of course, this is a /super/ special case where Java's constant
pool is involved. Someone who doesn't understand why "Pippo == "on"
doesn't always work is going to have their mind blown by the constant pool.
- -chris
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RE: [OT] "if" don't work?!?!?
> From: Jost Richstein [mailto:[EMAIL PROTECTED] > Subject: Re: [OT] "if" don't work?!?!? > > No, that is not guaranteed to be false. > For example >Pippo.intern() == Pluto.intern() > should be true. The above certainly is correct, but is not what the OP coded. - Chuck THIS COMMUNICATION MAY CONTAIN CONFIDENTIAL AND/OR OTHERWISE PROPRIETARY MATERIAL and is thus for use only by the intended recipient. If you received this in error, please contact the sender and delete the e-mail and its attachments from all computers. - To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: [OT] "if" don't work?!?!?
No, that is not guaranteed to be false.
For example
Pippo.intern() == Pluto.intern()
should be true.
Caldarale, Charles R schrieb:
From: Massimiliano PASQUALONI
[mailto:[EMAIL PROTECTED]
Subject: "if" don't work?!?!?
if (Pippo == "on") {
Guaranteed to be false.
Pippo = request.getParameter("abilitato");
Pluto = request.getParameter("abilitato");
the if (Pippo == Pluto ) don't work!
Also guaranteed to be false.
You need to learn Java before embarking on writing webapps for any
container. The test you're making is one for object equality, not
content equality. Your expression should be something like:
if (Pippo.equals("on"))
- Chuck
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--
Jost Richstein
SoftDeCC Software GmbH
Email: [EMAIL PROTECTED]
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Fax.: +49 89 89 06 78 33
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Re: OT: "if" don't work?!?!?
This is not really a Tomcat question, but a matter of Java language
understanding.
Comparators like ==, >, <=, etc. should only be used with java language
primitive types, such as int, byte, boolean, and NOT with Objects, like
String, as you are, UNLESS you actually wish to test whether the two
things you are comparing are the same object instance. To test whether
two distinct objects represent the same value or entity, use the equals
method. So in your case, you should use:
if (Pippo.equals("on")) { ... }
or
if (Pippo.equals(Pluto)) { ... }
Please respond to "Tomcat Users List"
To: "'Tomcat Users List'"
cc:
Subject:"if" don't work?!?!?
Hi guy!
Wat's happen??
If i read an checkrequest post
String Pippo = request.getParameter("abilitato");
out.print(Pippo);
return me= on
If I try to make a condition whit if:
if (Pippo == "on") {
}
these don't work
And is'nt the first time,
if I try
Pippo = request.getParameter("abilitato");
Pluto = request.getParameter("abilitato");
the if (Pippo == Pluto ) don't work!
:-(
please, help me!
Massimiliano PASQUALONI
Data Processing S.r.l.
Reparto EDP
S.S. 100 BA-TA Km 18
c/o "IL BARICENTRO"
torre D
70010 CASAMASSIMA (BA)
RE: [OT] "if" don't work?!?!?
> From: Massimiliano PASQUALONI
> [mailto:[EMAIL PROTECTED]
> Subject: "if" don't work?!?!?
>
>if (Pippo == "on") {
Guaranteed to be false.
> Pippo = request.getParameter("abilitato");
> Pluto = request.getParameter("abilitato");
>
> the if (Pippo == Pluto ) don't work!
Also guaranteed to be false.
You need to learn Java before embarking on writing webapps for any
container. The test you're making is one for object equality, not
content equality. Your expression should be something like:
if (Pippo.equals("on"))
- Chuck
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