query regarding assertion

[yogesh srinivasan]

I'm preparing for scjp 1.4

In this program

class Test
{
public static void main(String args[])
{
assert false;
}
}

i compiled using 1.4.2 JDK

D:\javatest>javac -d d:\javatest d:\javatest\package\Test.java
d:\javatest\package\Test.java:5: warning: as of release 1.4, assert is a keyword
, and may not be used as an identifier
assert false;
^
d:\javatest\package\Test.java:5: not a statement
assert false;
^
d:\javatest\package\Test.java:5: ';' expected
assert false;
^
2 errors
1 warning

BUT

D:\javatest>javac -source 1.4 -d d:\javatest d:\javatest\package\Test.java

I cant understand why assertion is not compiling when the source is not set, this was not happening for jdk 1.5

[Yeming Hu]

Although 1.4 and 1.5 both treat assert as a keyword, assertion is disabled for 1.4 by default while enabled for 1.5 by default when compiling. I believe K&B talks about it when it introduces assert so you can refer to it.