string reverse

[Yuan Tseng]

hi, everyone,
i was trying to do 'string reverse'. i have no compile error but when execute i got this error messages:
java.lang.ArrayIndexOutOfBoundsException
at Backwards.main(Backwards.java:10)
Exception in thread "main"

and this is the code:
for (i=0; i < str.length; i++);
System.out.print(str[i] + " ");
System.out.println ("\n");
please help me out.
thanks,
yuan

[Barry Gaunt]

 for (i=0; i < str.length; i++); 

Do you need that semicolon???
But that's not all the code is it?
[ April 02, 2003: Message edited by: Barry Gaunt ]

[Elouise Kivineva]

for (i=0; i < str.length(); i++)
{
System.out.print( str.charAt( i ) );
}

This will reel through a string named str from front to back. If you want to step through from back to front try this:

for ( i = (str.length() - 1 ) ; i >= 0 ; i-- )

Remember too that it's str.length if str is an array, but str.length() is str is a String.

[Peter den Haan]

One little tidbit to add:

for (i=0; i < str.length; i++);

Your problem, as stated above, is the semicolon. This closes the for statement, and you're simply looping str.length() times in an empty loop.
At the end of the loop, i has the value str.length(), which is why

System.out.print(str[i] + " ");

gives you an ArrayIndexOutOfBoundsException (remember, arrays indexes go from 0 to array.length-1).
- Peter

[Yuan Tseng]

Thanks for the help everyone...
yuan