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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!
Scanner scan = new Scanner(System.in);
B = scan.nextInt();
scan.nextLine();
H = scan.nextInt();
scan.close();
if(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");
}
else {
flag=false;
System.out.println("java.lang.Exception: Breadth and height must be positive");
}
What is the point of the elseif? what is the difference with the ouput of else?
In this exercice, there is no need to differentiate if one element is negative or both of them.
Static block is used to run code when a class is intialized or you can say before static void main function is called the static block will be run. so any calculations needed before the main funcation can be done in there. Hope this helps
@above No that code is too complicated. The else if statement is not neccessary (just need an else statement). You just need to set flag = true when both are greater than 0. (Lengths can't be negative)
your program is correct but how i am not able to understand the logic behind this
if ((B<0 && H<0)&&(B>=0&&H>=0))
suppose :we will give input 1and 3 then it shoud go to false block
because
B<0 && H<0 =false
B>=0&& H>=0=True
false && true
false should come
This one is the correct code you have written if block wrong.
static int B,H;
static boolean flag=true;
static{
Scanner scan = new Scanner(System.in);
B = scan.nextInt();
scan.nextLine();
H = scan.nextInt();
scan.close();
if(B>0 && H>0){
flag = true;
}else if((B<0 && H<0)||(B<=0 && H>=0)||(B>=0 && H<=0)){
flag=false;
System.out.println("java.lang.Exception: Breadth and height must be positive");
}
}
It won't give the correct answer. you need to remove the less than condition from the first if. other than that there is no need of second if else only else is needed.
It was not passing two test cases so i did some modification
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){
flag = true;
}else{
flag=false;
System.out.println("java.lang.Exception: Breadth and height must be positive");
}
}
static boolean flag = true;
static int B,H;
static{
Scanner scan = new Scanner(System.in);
B = scan.nextInt();
H = scan.nextInt();
scan.close();
if(B<=0||H<=0){
flag=false;
System.out.println("java.lang.Exception: Breadth and height must be positive");
}else
flag=true;
}
#this is the actual output
your output fails in two of the given test cases
Here i've just declared B,H as static variables because static methods involve use of static variables. flag is just initialized to default boolean value which can either be set as true or false doesn't make a difference.
Scanner sc = new Scanner(System.in);
B = sc.nextInt();
sc.nextLine();
H = sc.nextInt();
if(B>0 && H>0){
flag = true;
}else{
flag = false;
System.out.println("java.lang.Exception: Breadth and height must be positive");
}
}
the statement in if is unnecessary tho(greater than or equal to is not needed because it says to output area if only both are greater than 0, so its just better with B>0 && H>0)also the else if is unnecessary too. i use else there and it works just fine.
static
{
Scanner sc=new Scanner(System.in);
B = sc.nextInt();
sc.nextLine();
H = sc.nextInt();
sc.close();
if(B<=0 || H<=0)
System.out.println("java.lang.Exception: Breadth and height must be positive");
else
flag=true;
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'. "
public class Solution {
static boolean flag=false;
static int B,H;
static{
Scanner scan=new Scanner(System.in);
B=scan.nextInt();
H=scan.nextInt();
if(B>=0&&H>=0){
flag=true;
}
else{
System.out.println("java.lang.Exception: Breadth and height must be positive");
}
}
Isn't this incorrect? The if statement is going to give a false positive and allow a zero area. It should just be > not >=. I mean, it works with the test cases, I think, but it's not what the algorithm asked for.
I did it this way, too (using B > 0 && H > 0) but after reading everyone else's answers here initializing the flag to true and using B <= 0 || H <= 0 I realized that's technically more efficient because it wouldn't have to evaluated the second conditional statement if the first failed whereas using && will always require two comparisons.
Java Static Initializer Block
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Refer to this stackoverflow question if you'd like help understanding the difference between a static block and specific static initializers.
http://stackoverflow.com/questions/9379426/java-when-is-a-static-initialization-block-useful
I found this useful in comparison to the droves of wordy, example-less explanations (I'm looking at you, Oracle Docs.)
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.
becz since it is a static block all fields(variables) should be static it is similar to using static variables in static methods
Can you paste a link?
when we use static then we have not need to make a object .static functions invoke itself in java.
we use static because if we define our variables not in main class and we have to call them in it then we use static before our declaration.
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){ 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"); } else { flag=false; System.out.println("java.lang.Exception: Breadth and height must be positive"); }
}
What is the point of the elseif? what is the difference with the ouput of else? In this exercice, there is no need to differentiate if one element is negative or both of them.
why all code is written in static block plz explain(static{ ...........})
Static block is used to run code when a class is intialized or you can say before static void main function is called the static block will be run. so any calculations needed before the main funcation can be done in there. Hope this helps
tq
no object need to access members
it is a bad practice to just print the exception. you need to handle the exception using either try catch or throw/throws
thanks
That explains it.
cool
static boolean flag = true; static int B,H;
static{
}
@above No that code is too complicated. The else if statement is not neccessary (just need an else statement). You just need to set flag = true when both are greater than 0. (Lengths can't be negative)
https://stackoverflow.com/questions/2070293/why-doesnt-java-allow-to-throw-a-checked-exception-from-static-initialization-b
You have a error in else if() block
Here is the actual answer
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)||(B<=0 && H>=0)) { flag=false; System.out.println("java.lang.Exception: Breadth and height must be positive"); } }
your program is correct but how i am not able to understand the logic behind this if ((B<0 && H<0)&&(B>=0&&H>=0)) suppose :we will give input 1and 3 then it shoud go to false block because B<0 && H<0 =false B>=0&& H>=0=True false && true false should come
why so many comparison operator dude. Simply below would work just fine.
static boolean flag = true; static int B, H; static Scanner sc = new Scanner(System.in);
static { B = sc.nextInt(); H = sc.nextInt();
What if B and H are Both 0?
Better be B<0 || H<0.
If both are 0, there should be an Exception, it's written in the task:
it doesn't works fine. it gives some expression error bcoj u use static keyword before Scanner class.....
This works
static int B,H; static boolean flag=true; static Scanner sc=new Scanner(System.in); static{ B=sc.nextInt(); sc.nextLine(); H=sc.nextInt(); sc.close(); if((B>=0&&H>=0)&&(B!=0&&B!=100)&&(H!=0&&H!=100)){ flag=true; }else{ flag=false; System.out.println("java.lang.Exception: Breadth and height must be positive"); }
why did we keep the whole loop in a static block
it doesn't matter
if not, it is throwing an error
i am not able to get area output
what is the use of nextLine() bro
It is just to clear the previous String or we can say to clear the String garbage.
This one is the correct code you have written if block wrong. static int B,H; static boolean flag=true; static{ Scanner scan = new Scanner(System.in); B = scan.nextInt(); scan.nextLine(); H = scan.nextInt(); scan.close(); if(B>0 && H>0){ flag = true;
}else if((B<0 && H<0)||(B<=0 && H>=0)||(B>=0 && H<=0)){ flag=false; System.out.println("java.lang.Exception: Breadth and height must be positive"); } }
It won't give the correct answer. you need to remove the less than condition from the first if. other than that there is no need of second if else only else is needed.
can you explain how you directly used B,H as variables instead specifying any datatypes for that.
He used int .Read carefully you can find it.
It was not passing two test cases so i did some modification
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){ flag = true;
}else{ flag=false; System.out.println("java.lang.Exception: Breadth and height must be positive"); } }
thanks..this is giving correct answer. I was missing to update the flag as false in else loop.
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){ flag = true;
}else{ flag=false; System.out.println("java.lang.Exception: Breadth and height must be positive"); } }
static boolean flag = true; static int B,H;
static{ Scanner s=new Scanner(System.in); B=s.nextInt(); s.nextLine(); H=s.nextInt(); s.close(); if(H<=0 || B<=0){ flag=false; System.out.println("java.lang.Exception: Breadth and height must be positive"); } }
static boolean flag = true; static int B,H; static{ Scanner scan = new Scanner(System.in); B = scan.nextInt(); H = scan.nextInt(); scan.close(); if(B<=0||H<=0){ flag=false; System.out.println("java.lang.Exception: Breadth and height must be positive"); }else flag=true; }
why we should keep in static block?
yr god has got some errors here is the errorless code
/............................................./ 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) { flag = true;
} else if((B<=0 && H>=0)||(B>=0 && H<=0)||(B<=0 && H<=0)) { flag=false; System.out.println("java.lang.Exception: Breadth and height must be positive"); } }
Your If and else if conditions are wrong. keep it simple silly.
if(B>0 && H>0){ flag = true;
}else { flag=false; System.out.println("java.lang.Exception: Breadth and height must be positive"); }
your solution satisfies only problem's requirements but my solution covers all possibilities.
Why we use static block here
This is because we have been told to use static block in this problem.
thanks bro
static boolean flag = true; static int B,H; please explain this.....
Here i've just declared B,H as static variables because static methods involve use of static variables. flag is just initialized to default boolean value which can either be set as true or false doesn't make a difference.
this is not satisfying few test cases even
It should, it worked fine for me which is why i posted my code.
ok!!thanku
Your code gives wrong answer in some test case insted do this :-
if(B>0 && H>0){ flag = true;
}else{ flag=false; System.out.println("java.lang.Exception: Breadth and height must be positive"); }
yes!!there r few cases which r not satisfying...but mild changes can be done the some code
// Much simpler one.
Scanner sc = new Scanner(System.in); B = sc.nextInt(); sc.nextLine(); H = sc.nextInt(); if(B>0 && H>0){ flag = true; }else{ flag = false; System.out.println("java.lang.Exception: Breadth and height must be positive"); } }
In this testcas 3 and 6 become failed.
What's the reason for usage of scan.nextLine() here? will you please explain !
the statement in if is unnecessary tho(greater than or equal to is not needed because it says to output area if only both are greater than 0, so its just better with B>0 && H>0)also the else if is unnecessary too. i use else there and it works just fine.
static int B; static int H; static boolean flag;
static { Scanner sc=new Scanner(System.in); B = sc.nextInt(); sc.nextLine(); H = sc.nextInt(); sc.close(); if(B<=0 || H<=0) System.out.println("java.lang.Exception: Breadth and height must be positive"); else flag=true;
}
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
Agree, especially with such a simplistic example, the motivation for using this made so little sense to me.
thanks for your cooperation
thanks bro..
public class Solution { static boolean flag=false; static int B,H; static{ Scanner scan=new Scanner(System.in); B=scan.nextInt(); H=scan.nextInt(); if(B>=0&&H>=0){ flag=true; } else{ System.out.println("java.lang.Exception: Breadth and height must be positive"); } }
Isn't this incorrect? The if statement is going to give a false positive and allow a zero area. It should just be > not >=. I mean, it works with the test cases, I think, but it's not what the algorithm asked for.
I did it this way, too (using B > 0 && H > 0) but after reading everyone else's answers here initializing the flag to true and using B <= 0 || H <= 0 I realized that's technically more efficient because it wouldn't have to evaluated the second conditional statement if the first failed whereas using && will always require two comparisons.
Am I being crazy? XD
that's so intersting....