And the commands:
javac Test.java
java ea Test
What is the result?
A.
Compilation fails
B.
Standard Edition
Enterprise Edition
Micro Edition
C.
Standard Edition
class java.lang.AssertionError
Micro Edition
D.
Standard Edition is printed and an Assertion Error is thrown
Explanation:
javac Test.java
will compile the program.
As for command line:
java ea Test
First the code will produce the output:
Standard Edition
See Note below.
The ea option will enable assertions. This will make the following line in the switch statement to be
run:
default: assert false;
This will throw an assertion error. This error will be caught. An the class of the assertion error
(classjava.lang.AssertionError) will be printed by the following line:
System.out.println(e.getClass());
Note:The java tool launches a Java application. It does this by starting a Java runtime
environment, loading aspecified class, and invoking that class’s main method. The method
declaration must look like the following:
public static void main(String args[])
Paramater ea:
-enableassertions[:<package name>”…” | :<class name> ] -ea[:<package name>”…” | :<class
name> ]
Enable assertions. Assertions are disabled by default. With no arguments, enableassertions or -ea
enablesassertions.
Note 2:
An assertion is a statement in the JavaTM programming language that enables you to test your
assumptionsabout your program.
Each assertion contains a boolean expression that you believe will be true when the assertion
executes. If it isnot true, the system will throw an error.
public class AssertionError extends ErrorThrown to indicate that an assertion has failed.
Note 3:
The javac command compiles Java source code into Java bytecodes. You then use the Java
interpreter – the
java command – to interprete the Java bytecodes.
Reference:java – the Java application launcher
Reference:java.langClass AssertionError
D
To enable assertion, the input parameter should be “-ea” instead of “ea”.