#Bit-Operation

1 messages · Page 1 of 1 (latest)

weak crypt
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im trying to solve this task.
so far i converted the right-expression of xor into

1010 1010

2
0010 1010

my problem lies in the left-expression

when i convert 0x99 into decimal i get 153.

how am i supposed to shift 2 = 0010
153 positions to the left ?

tassdwd.PNG
misty meadowBOT
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<@&987246399047479336> please have a look, thanks.

urban abyss
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its the other way around

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you shift 0x99 to the left twice

weak crypt
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realy ?
0xaa is 170
so i shift 2 170 times to the right ?

urban abyss
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no, you shift 0xaa to the right twice

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the left side of <</>> gets shifted by the amount specified on the right side

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left << right

weak crypt
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is the amount of shifts not in the position after the arrow ?

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___ <<

shadow adder
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no

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otherwise both would do the same thing

weak crypt
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32

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is the correct answer

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yey

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what would i do without you two

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😂

urban abyss
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all good

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problem was just a misunderstanding of the syntax

weak crypt
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yup

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are you bachelor students ?

urban abyss
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no

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I just finished school

weak crypt
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wow so you are young ?

urban abyss
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kinda?

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im 18

weak crypt
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well 32 is wrong xD

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14 is right

shadow adder
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guys

weak crypt
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i did && instead of XOR lol

shadow adder
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you know you can just run the code right ?

weak crypt
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its a test, i must do it on paper

misty meadowBOT
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Alathreon's result

Snippets

Snippet 30, VALID

(0x99<<2)^(0xaa>>2)```
jshell> `590`
## System out
[Nothing]
shadow adder
urban abyss
weak crypt
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yes online test.
similar tasks will probably be in the exam

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i cant use IDE there

shadow adder
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if it is a test we can't help you any longer

urban abyss
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you are not supposed to run the code, instead the task is to understand these

urban abyss
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just not spoonfeeding

weak crypt
shadow adder
urban abyss
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its not?

urban abyss
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seems like they are learning for it

weak crypt
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im converting the hex numbers to decimal

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and then into binary

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on paper

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and manually solving the expression on paper

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but im not sure why it says
char a ?

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one char has 1 byte

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and 14 has 4 bit

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14 would also be the solution for int a ?

shadow adder
weak crypt
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one char has 2 byte ?

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thats 2^8

charr.PNG
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8bit = 1 byte

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or no ?

shadow adder
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no

urban abyss
misty meadowBOT
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Alathreon's result

Snippets

Snippet 23, VALID

(int)Character.MAX_VALUE```
jshell> `65535`
## System out
[Nothing]
shadow adder
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you know that they are constants for this right ?

shadow adder
weak crypt
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are there definition differences ? because for C it says char has one byte

shadow adder
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In C yes

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but java is a different language from C

weak crypt
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🤯

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ok learned something new

shadow adder
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...

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also

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isn't char size unspecified in c ?

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actually it seems to be specified as one byte

weak crypt
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one byte

shadow adder
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one of the few primitives that has a fixed size

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compared to c where size may be random

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in java, all primitives are totally defined

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all primitives except boolean and char are signed

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byte is one byte
short and char are two bytes
int and float are four bytes
long and double are height bytes

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and note that those sizes are what you can put inside, their actual size in the computer is undefined

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@weak crypt

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@weak crypt also, do you know why java char is two bytes ?

weak crypt
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not sure because ascii only needs 7 bits to display all characters

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that means 8 bit sounds better

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maybe to display additional characters ?

shadow adder
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ascii isn't near enough

weak crypt
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japanes letters ? 😄

shadow adder
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and well, yes it's enough to display most english characters

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but it can't display characters from any other language

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like é in french

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or whatever other language have

shadow adder
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and then you also have symbols

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like math symbols

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or country symbols

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and then you have emojis

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which yes are characters

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so in order to display all characters in utf8, you need 4 bytes

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and while java knew that they needed more than one byte to make it work
I don't think they predicted that it would actually take 4 bytes pepekek

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so anyway

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c's char is bad
java's char is better but still meh

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because the correct answer was 4

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-_-

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ah and just so you know

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characters that are often used but maybe not in english are usually on two bytes

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and weird characters like emojis are on four bytes

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@weak crypt

weak crypt
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are you a student ?

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or have an academic

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grade

shadow adder
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I'm doing a master

weak crypt
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coool

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do logical operators work on integers ?

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i think they dont

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ah k

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0 interpreted as false

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anything else as true

shadow adder
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it shouldn't compile

weak crypt
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don't ? xD

shadow adder
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but you marked this channel as java

urban abyss
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looks like c to me

shadow adder
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so I assume you are talking about java

weak crypt
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ahh sry

shadow adder
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well

weak crypt
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i think i need to switch channels for c specific questions

shadow adder
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actually no

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my bad

urban abyss
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lmao

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it can be, but its missing context

weak crypt
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are c questions also good in this channel ?

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im doing a bit

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c

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java tasks are done

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for now

shadow adder