Assertion again.

[Vishy Karl]

Hi all ,
another one from javacertificate.com
Which of the following statements will compile AssertTest.java to use assertions?


1 javac -ea AssertTest.java
2 javac -enableassertions AssertTest.java
3 javac AssertTest.java
4 javac -source 1.4 AssertTest.java

Answer given is 4. why is it so ??
TIA.

[Gian Franco]

Originally posted by Vishy Karl:
Hi all ,
another one from javacertificate.com
Which of the following statements will compile AssertTest.java to use assertions?


1 javac -ea AssertTest.java
2 javac -enableassertions AssertTest.java
3 javac AssertTest.java
4 javac -source 1.4 AssertTest.java

Answer given is 4. why is it so ??
TIA.

Assertions where added in Java 1.4. If you compile with
the option Java 1.3, assertions won't be considered at
all and you can even use the word assert as a method name
for example.
In order to 'activate' assertions during run-time you will
have to use the flag -ea. But of course this is only possible
if you compiled with the Java 1.4 option.
Greetings,
Gian Franco

[Vicken Karaoghlanian]

Originally posted by Vishy Karl:
Answer given is 4. why is it so ??

Because that's the way it is. 'source' is used to provide compatibilty with the specific release (in your case 1.4)
The first two are used with the 'java' command not 'javac', it is used to enable assertion at runtime.
The third one is used to compile a normal source file that does not contain the 'assert' keyword.