Wednesday, January 27, 2010

SCJP exercise : operators

Exercise :



Given the following :

public class Test {


public static void main(String [] args) {

int num = 1;
if ( num == 'a') {
System.out.println("Good result !");
} else {
System.out.println("Result:" + num);
}
}

}


What is the result ? (choose one)

A Good result !
B Result:1
C Compilation fails
D An exception is thrown at runtime






Solution :


The result is C.There is no compilation error.You can compare 1 with 'a' because the comparison use the unicode value of a.So it's correct to compare 1 with 'a'.

Wednesday, January 20, 2010

SCJP exercise : operators

An other exercise ! The goal is practice and learn commons java certification SCJP questions.

Exercise :



Given the following :

public class Test {

public static void main(String [] args) {


int num = 1;

if ( num = 2) {

System.out.println("Result:" + num);

}

System.out.println("Result:" + num);

}

}



What is the result ? (choose one)


A Result:1

B Result:2

C Compilation fails

D An exception is thrown at runtime






Solution :


The solution is C.In fact we set num to 2 with num=2.
So the result of the setting is an int.Or the if is waiting a boolean so the compilation fails.

Thursday, January 7, 2010

Good year

Hi !

This year we will see many things like certification exercise, Java tips, Go langage ...
So it's exiting !