What is the result?

Given:

public class Counter {

public static int getCount(String[] arr) {

int count =0 ;

for(String var:arr) {

if(var!=null) count++;

}

return count;

}

public static void main(String[] args) {

String[] arr =new String[4];

arr[1] = “C”;

arr[2] = “”;

arr[3] = “Java”;

assert (getCount(arr) < arr.length);

System.out.print(getCount(arr));

}

}

And the commands:

javac Counter.java

java ea Counter

What is the result?

A.
2

B.
3

C.
NullPointException is thrown at runtime

D.
AssertionError is thrown at runtime

E.
Compilation fails

Explanation:
The command line javac Counter.java
will compile the code.
The command line java ea Counter
will run the cod with assertions enabled.

The following line:
assert (getCount(arr) < arr.length);
where the Boolean expressiongetCount(arr) < arr.lengthwill evaluate to false, will ensure that anAssertionError is thrown at runtime.

Note:The javac command compiles Java source code into Java bytecodes. You then use the Java interpreter – the java command – to interprete the Java bytecodes.

Note 2:The java tool launches a Java application. It does this by starting a Java runtime environment, loading a specified 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 enables assertions.

Note 3:
An assertion is a statement in the JavaTM programming language that enables you to test your assumptions about your program.
Each assertion contains a boolean expression that you believe will be true when the assertion executes. If it is not true, the system will throw an error.