Clean and Clear. Perfect. Thanks. Yea, Oracle Docs has a lot to read.

Really helpful. Thanks.

thanks.

I generally avoid coming here to discussions as people post answers! But when all seemed lost and there was no hope left for humanity. You came in my friend! ALL HAil our lord and saviour Stefank!

thanku so much ..... it clears all doubt

Thanks for this link. It helped me to understand this concept in more better way

thank u bro..now I got the point.

Thanks!It's very useful and helpful.

static Scanner in=new Scanner(System.in); static int B=in.nextInt(); static int H=in.nextInt(); static boolean flag=true;

why did we add static? couldn't get.I am new for Java.

thanks

That explains it.

cool

static boolean flag = true; static int B,H;

static{

Scanner scan = new Scanner(System.in);
B = scan.nextInt();
scan.nextLine();
H = scan.nextInt();
scan.close();
if((B<=0 && H<=0)||(B>=0 && H>=0)){
    flag = true;

}else if((B<=0 && H>=0)||(B>=0 && H<=0)){
    flag=false;
    System.out.println("java.lang.Exception: Breadth and height must be positive");
}

}

What's missing from all these explanations is they all focus on "how it works" and not "why you would want to do it" which remains still partiallly a mystery to me. Apart from allowing one to run commands out of sequence - and why would you want to do that? - the best explanation of what it's for that I could find is...

"The advantage of private static methods is that they can be reused later if you need to reinitialize the class variable. So, you kind of get more flexibility with a private static method in comparison to the corresponding static initialization block. This should not mislead that a 'public' static method can't do the same. But, we are talking about a way of initializing a class variable and there is hardly any reason to make such a method 'public'. "

http://www.jusfortechies.com/java/core-java/static-blocks.php

Great example! :)

This problem does not require exceptions. It's actually way easier without them.

how multiplication result comes automatically?

But why use try-catch?

Understood the problem but I felt like it lack explanition. Thank you for the example! Now I understand it clearly. I probably would've gotten it if I had known you could expand the code by clicking on the blue arrows.

why do we use static in every line??

thanks,this cleared my doubt!!!!

Mine is much simpler. I just print the string literally without throwing any exception XD. Because it doesn't make sense to throw an exception on a static block. It should be either in the constructor or in a method.

I'm already an experienced developer and I found this while looking places to practice my coding skills. These challenges are too easy for me XD. But they are good to remember the basics.

I've been coding in Python for a year or so. During this period I almost didn't touched Java. That's why I wanted to practice it a little bit.

Sorry, this went totally out of topic... I just felt I had to say it.

i use try-with-resources to create new Scanner. ( like this try (Scanner scanner = new Scanner(System.in)) ) because Scanner may be need close for good practice .

why we need static here

what is the use of flag here?

how is this code giving the result of the parallelogram?

I thought static block was mainly used to initialize variables. It gives error if I add declaration in static block. Any Suggestions?

good one. help to identify improve on my sloution

sir i have a doubt as i m new to java ..... Exception is written class in java ... can we throw it tooo...??

Thank you for helping.

Thanks, that helped out a lot. I did mine differently but I didn't know you had to define the variables outside of the static block for them to be static.

what if we don't use static flag variable?

Nice solution! Please elaborate the use of 'throw' keyword here..

we are declaring flag as static boolean flag=true. As it is static so it shouldn't make changes but when inside the static block we give flag=false,the flag becomes false.Why?

but its not running

I don't think the try catch is necessary. Just use println is OK;

//Write your code here
static boolean flag = true;
static int B, H;
static {
    Scanner scanner = new Scanner(System.in);
    B = scanner.nextInt();
    scanner.nextLine();
    H = scanner.nextInt();
    scanner.close();
    if (B <= 0 || H <=0){
        flag = false;
        System.out.println("java.lang.Exception: Breadth and height must be positive");
    }
    else {
        //System.out.println(B * H);
    }
}

bro where is the product (area of parallelogram ) shown

can some body explain the role of flag in the above example ?? why do we need a flag , what does it do?i tried the code without the flag but it dosent work!please help

Why do you need to use static for Scanner, boolean, and int?

A shorter approach

private static Scanner scan = new Scanner(System.in); private static boolean flag = false; private static int B = scan.nextInt(); private static int H = scan.nextInt();

static{

flag = (B>0 && H>0);

if(!flag)
{System.out.print("java.lang.Exception: Breadth and height must be positive");}

}

public static Scanner sc = new Scanner(System.in);
public static int B = sc.nextInt();
public static int H = sc.nextInt();
public static boolean flag = init2();


private static boolean init2(){
    if(B<=0 || H<=0){
        System.out.println("java.lang.Exception: Breadth and height must be positive");
        return false;
    }
    return true;
}

Without try-catch block

why only try and catch blocks are used why we cant use if-else block can u plzz explain ??

Why u used flag ?

what is the use of flag? not used any where

well defined and easy to understand try - catch, code. Thanks!

thanks , i am now clear with our logic

The exercise calls "Java Static Initializer Block" for a reason. =) To teach how to use Static Initializer Block. Sure it's easy to do the same thing in the main class.

I think the way should be used when you wan't make sure the code is called before any other. And the code will not relay on the current coder to invoke.

You can keep the end as simple as: if(!(flag = B > 0 && H > 0)) System.out.println("java.lang.Exception: Breadth and height must be positive");

Since you want to keep it simple lol.

Btw I don't recommend caching an object such as Scanner like that. Its a habit habit for big apps. It won't be deleted from memory that way even thought its not used anywhere else.

this could also be tried to simplify a bit the above code.

static boolean flag = true;

static Scanner sc = new Scanner(System.in);

static int B = sc.nextInt();

static int H = sc.nextInt();

static{

if(B<=0 || H<=0){
    flag = false;
    System.out.println("java.lang.Exception: Breadth and height must be positive");
}

}

I liked you actually throw the exception :)

Hi austinoyugi! Nice. I used

throw new java.lang.Exception("Breadth and height must be positive");

and

    catch (java.lang.Exception e) {
        System.out.println(e.toString());
        }