On Wednesday, 11/27/2002 at 09:36 EST, "Spencer W. Thomas"
<[EMAIL PROTECTED]> wrote:
> || is not "exclusive or". It is just "inclusive or" with short-circuit
> evaluation -- it doesn't evaluate the second operand if the first is
> already true.
Bingo. Similar for && vs. & -- operator && short-circuits (i.e. does not
evaluate the second operand if the first is false), while operator & does
not.
> The result from (n < 0) || (n != 0) is EXACTLY THE SAME
> as the result from (n < 0) | (n != 0). The first expression is slightly
> more efficient when executed, that's all.
...when n is negative, and the short-circuit "fires".
Predict the output of this little toy class (answer below)
public class X {
public static void main( String[] args ) {
Object o = null;
try {
if ( ( null == o ) || "foo".equals( o.toString() ) ) {
System.out.println( "Now is the time " );
}
if ( ( null == o ) | "foo".equals( o.toString() ) ) {
System.out.println( "...for all good men" );
}
} catch ( NullPointerException npe ) {
System.out.println( "...to come to the aid of their country" );
}
}
}
Output:
$ java X
Now is the time
...to come to the aid of their country
Fun stuff, this.
-blair
____________________________________________________
To change your JDJList options, please visit:
http://www.sys-con.com/java/list.cfm
Be respectful! Clean up your posts before replying
____________________________________________________
