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converting string to integer

Ann-Marie Russell
Greenhorn

Joined: Sep 29, 2004
Posts: 6
I am new to Java, coming from VB.NET. In VB it is rather simple to convert from any single datatype to another by doing a ctype(). I am trying to convert a string to an integer using java. I know that i can conver types such as a float to an integer using: int blah = (int) float but i receive an error when trying to do this to a string...any words of advice are welcome.

thanks,
AMR


amr04
David Ulicny
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Joined: Aug 04, 2004
Posts: 724
int i = Integer.parseInt("1");
int j = new Integer("1").intValue();


SCJP<br />SCWCD <br />ICSD(286)<br />MCP 70-216
Ernest Friedman-Hill
author and iconoclast
Marshal

Joined: Jul 08, 2003
Posts: 24183
    
  34

Hi Ann-Marie,

Welcome to JavaRanch!

The static method java.lang.Integer.parseInt() is one way to do this:



Likewise, there's a parseDouble() in java.lang.Double, a parseFloat() in java.lang.Float(), etc. These methods report failure -- i.e., a String that doesn't look like a valid number -- by throwing NumberFormatException; a proper program has to catch and deal with that error.


[Jess in Action][AskingGoodQuestions]
Ramaswamy Srinivasan
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Joined: Aug 31, 2004
Posts: 295
Hi Ann-Marie,

I agree with this way of converting types suggested by Ernst.

String s = "35"; int i = Integer.parseInt(s);


And thanks Ernst for the insight into other parseXXXX() methods.

I came across a good deal of information on Casting and datatypes in the book Head First Java - by Kathy Sierra & Bert Bates.
You can get a good start, especially if u r starting with Java.

Cheers,
Swamy
Chengwei Lee
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Joined: Apr 02, 2004
Posts: 884
Don't forget to put your codes in a try-catch block, you never know when the string argument that you're receiving could turn out to be unparsable.


SCJP 1.4 * SCWCD 1.4 * SCBCD 1.3 * SCJA 1.0 * TOGAF 8
Ramaswamy Srinivasan
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Joined: Aug 31, 2004
Posts: 295
Hi Cheng...



string argument that you're receiving could turn out to be unparsable


Thanks for pointing that out. If you don't mind, can u give some elaboration on the Unparsable Strings. Like some instances where this can happen?

Cheers,
Swamy
Jeff Bosch
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Joined: Jul 30, 2003
Posts: 804


Give a man a fish, he'll eat for one day. Teach a man to fish, he'll drink all your beer.
Cheers, Jeff (SCJP 1.4, SCJD in progress, if you can call that progress...)
Nigel Browne
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Joined: May 15, 2001
Posts: 673
or maybe
Mark Vedder
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Joined: Dec 17, 2003
Posts: 624

Originally posted by Ramaswamy Srinivasan:
If you don't mind, can u give some elaboration on the Unparsable Strings. Like some instances where this can happen?

Originally posted by Jeff Bosch:


Or the equally as bad, but maybe less obvious:



The following would work (i.e. not throw an exception)...

Ramaswamy Srinivasan
Ranch Hand

Joined: Aug 31, 2004
Posts: 295
Hi all,

Thanks a lot guys, for making the thing clear..

Cheers,
Swamy
 
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