How do I use try catch to catch an array out of bounds exception? | Java Community | Help. Code. Learn. | Page 1

neat scroll Sep 28, 2023, 5:57 AM

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strong elkBOT Sep 28, 2023, 5:57 AM

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neat scroll Sep 28, 2023, 5:59 AM

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im just confused how to use those variables above into the try statment

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maybe i should change the exception, but i honestly am not sure about all the exceptions

compact salmon Sep 28, 2023, 5:59 AM

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neat scroll

you really shouldn't need to do this, this exception is thrown when you are trying to access an element in array at the wrong index

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you can just check the index's value if you want to run code when it's outside the range

neat scroll Sep 28, 2023, 6:00 AM

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oh

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no reason for try catch then?

compact salmon Sep 28, 2023, 6:01 AM

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yeah

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just use and if statement

neat scroll Sep 28, 2023, 6:01 AM

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okie i will attempt this!

compact salmon Sep 28, 2023, 6:01 AM

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but then again you method name is leading me to believe this is an xy problem

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https://en.wikipedia.org/wiki/XY_problem

XY problem

The XY problem is a communication problem encountered in help desk, technical support, software engineering, or customer service situations where the question is about an end user's attempted solution (Y) rather than the root problem itself (X).The XY problem obscures the real issues and may even introduce secondary problems that lead to miscomm...

neat scroll Sep 28, 2023, 6:03 AM

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compact salmon but then again you method name is leading me to believe this is an xy problem

like i didnt give enough info?

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yea probably

compact salmon Sep 28, 2023, 6:03 AM

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well what are you actually trying to achieve

neat scroll Sep 28, 2023, 6:04 AM

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averageInRange(new int[]{1, 2, 3, 4, 5, 6, 7, 8}, 2, 5) should return 4.5 and

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averageInRange(new int[]{1, 2, 3, 4, 5, 6, 7, 8}, 5, 2) should return 0.0.

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cause its not in range

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I think i did it!?

compact salmon Sep 28, 2023, 6:05 AM

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well if I input an index outside the indices of the array, what happens?

neat scroll Sep 28, 2023, 6:05 AM

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ah shit i gotta try that

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yea an exception

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another if statement then?

compact salmon Sep 28, 2023, 6:07 AM

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you only need one if statement

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it's the location of that if statement that matters

neat scroll Sep 28, 2023, 6:12 AM

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location?

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i tried something like this

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but didnt work still got an exception

compact salmon Sep 28, 2023, 6:12 AM

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look at your error

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where is it orginating from in your code, what line

neat scroll Sep 28, 2023, 6:13 AM

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out of bounds

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tried setting indexStart as 9

compact salmon Sep 28, 2023, 6:13 AM

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there should be a more speicifc location, like inside the method itself

neat scroll Sep 28, 2023, 6:13 AM

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maybe 63?

compact salmon Sep 28, 2023, 6:13 AM

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can you copy and paste the stacktrace?

neat scroll Sep 28, 2023, 6:13 AM

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the what now

compact salmon Sep 28, 2023, 6:14 AM

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the red message

neat scroll Sep 28, 2023, 6:14 AM

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Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: Index 9 out of bounds for length 8
at assign04.MethodPractice.averageInRange(MethodPractice.java:52)
at assign04.MethodPractice.main(MethodPractice.java:80)

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oh

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80 and 52?

compact salmon Sep 28, 2023, 6:14 AM

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alright, look at this line assign04.MethodPractice.averageInRange(MethodPractice.java:52)

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line 52 yeah

neat scroll Sep 28, 2023, 6:14 AM

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whats wrong with that?

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it was working before

compact salmon Sep 28, 2023, 6:15 AM

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it's throwing there because your doing the following arr[some index less than 0 or greater than/equal to the length]

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arr is some array

neat scroll Sep 28, 2023, 6:16 AM

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oh

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so do i need to move it up

compact salmon Sep 28, 2023, 6:16 AM

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so you want to check the index before this happens

neat scroll Sep 28, 2023, 6:16 AM

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an if statement at the beginning

compact salmon Sep 28, 2023, 6:16 AM

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yes

neat scroll Sep 28, 2023, 6:17 AM

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bruh

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it was that simple 😭

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so is writing 2 if statements like this fine

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or does this look like bad writing

compact salmon Sep 28, 2023, 6:18 AM

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it's incorrect and ugly :/

neat scroll Sep 28, 2023, 6:19 AM

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😭

compact salmon Sep 28, 2023, 6:19 AM

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what happens if either is -5 for instance

neat scroll Sep 28, 2023, 6:20 AM

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sigh

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another failure

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cant do smth like > || < like greater OR less than

compact salmon Sep 28, 2023, 6:21 AM

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try it

neat scroll Sep 28, 2023, 6:22 AM

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i did

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invalid expression

compact salmon Sep 28, 2023, 6:23 AM

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oh I read that as can

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can you show the code

neat scroll Sep 28, 2023, 6:23 AM

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with the failed expression?

compact salmon Sep 28, 2023, 6:23 AM

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sure

neat scroll Sep 28, 2023, 6:23 AM

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compact salmon Sep 28, 2023, 6:24 AM

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yeah that's no good, you need to be explicit. value > is not a boolean expression

neat scroll Sep 28, 2023, 6:25 AM

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well what are we trryna fix first tho

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how do i make it like proper format

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the "clean" way i guess?

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my code is ugly hidethepain

compact salmon Sep 28, 2023, 6:26 AM

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indexStart < 0 is a boolean expression

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so you could try implementing that into your code

neat scroll Sep 28, 2023, 6:27 AM

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huh

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so is this uglier

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LMAO

compact salmon Sep 28, 2023, 6:27 AM

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you want to check if the indexStart is less than 0

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idk what that is lol

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stop guessing!

neat scroll Sep 28, 2023, 6:28 AM

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no i mean it WORKS

compact salmon Sep 28, 2023, 6:28 AM

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no it doesn't

neat scroll Sep 28, 2023, 6:28 AM

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wym

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it checks if its greater or less than arraylength

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and now it returns 0.0

compact salmon Sep 28, 2023, 6:28 AM

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yeah but again -5 is less than arraylength

neat scroll Sep 28, 2023, 6:28 AM

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compact salmon Sep 28, 2023, 6:29 AM

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wait, bad example

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now if fails when the it's actually a valid index

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any index less than the length now returns 0

neat scroll Sep 28, 2023, 6:29 AM

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oh

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fml

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but i did check if index was less than 0 though?

compact salmon Sep 28, 2023, 6:31 AM

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no

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you only checked if it was less than the length

neat scroll Sep 28, 2023, 6:31 AM

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o

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ok holdup

compact salmon Sep 28, 2023, 6:32 AM

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you should check if either index is less than 0 or greater/equal to the length

neat scroll Sep 28, 2023, 6:32 AM

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oh

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u mean like combien it into 2 lines instead of 4

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compact salmon Sep 28, 2023, 6:34 AM

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you're almost there

neat scroll Sep 28, 2023, 6:34 AM

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HUHH

compact salmon Sep 28, 2023, 6:34 AM

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array[0] is accessing the element in the array

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that has nothing to do with what you are checking

neat scroll Sep 28, 2023, 6:36 AM

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compact salmon you should check if either index is less than 0 or greater/equal to the length

oh

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u meant like int 0

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compact salmon Sep 28, 2023, 6:36 AM

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yes

neat scroll Sep 28, 2023, 6:36 AM

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ok i read that wrong and was like

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array[0] lol

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alright well i think its good now?

compact salmon Sep 28, 2023, 6:38 AM

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if you still have the check for the startIndex being greater than the endIndex, then sure

neat scroll Sep 28, 2023, 6:38 AM

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yea at the bottom

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tysm karter i would have def forgotten to like check all that

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negatives and out of bounds

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etc

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and i learned how to finally use the || or statement now

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now i gotta watch some of my cs lectures and hope i dont fall behind

compact salmon Sep 28, 2023, 6:42 AM

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the logic itself seems flawed but maybe thats a problem for another time? lol

neat scroll Sep 28, 2023, 6:42 AM

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HU

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wym 😭

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my code?

compact salmon Sep 28, 2023, 6:42 AM

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you're just getting the average of the range right?

neat scroll Sep 28, 2023, 6:42 AM

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yea

compact salmon Sep 28, 2023, 6:42 AM

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so why are you adding the index to each element lol

neat scroll Sep 28, 2023, 6:43 AM

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o

compact salmon Sep 28, 2023, 6:43 AM

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I guess that's a 1 not an i

neat scroll Sep 28, 2023, 6:43 AM

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wait a min

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does it only work because the array is 1,2,3,4,5,6,7

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shit

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NOOOOOO

compact salmon Sep 28, 2023, 6:43 AM

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it works if the index are messed up lol

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because that's what we just worked on

neat scroll Sep 28, 2023, 6:44 AM

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are u talking about this

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or

compact salmon Sep 28, 2023, 6:44 AM

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your loop

neat scroll Sep 28, 2023, 6:44 AM

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this

compact salmon Sep 28, 2023, 6:44 AM

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what is it doing exactly

neat scroll Sep 28, 2023, 6:44 AM

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because this was also just a guess

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but it printed out the right numbers

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so

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i was like ill take it

compact salmon Sep 28, 2023, 6:45 AM

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if you want to get you code right, you need to stop guessing 😭

neat scroll Sep 28, 2023, 6:45 AM

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oh

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was this loop completely pointless

compact salmon Sep 28, 2023, 6:46 AM

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no you need to calculate the average still

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a loop can help you with that

neat scroll Sep 28, 2023, 6:46 AM

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well my loop did nothing tho

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right

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or nothing useful'

compact salmon Sep 28, 2023, 6:46 AM

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yes because your average is calculated incorrectly

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you aren't averaging the indices, you're averaging the elements in the range

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,ask eval (3+4+5+6)/4

hollow smeltBOT Sep 28, 2023, 6:47 AM

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compact salmon Sep 28, 2023, 6:47 AM

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(3,4,5,6) are your elements in your range (if the range was [2,5])

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4 is the number of elements

neat scroll Sep 28, 2023, 6:48 AM

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wait so array[i]+=1

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am i making 3,4,5,6 into 4,5,6,7?

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or am i makin it go to the next element in the array and adding that

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like 3+4+5+6

compact salmon Sep 28, 2023, 6:48 AM

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neat scroll am i making 3,4,5,6 into 4,5,6,7?

yes

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you shouldn't need to change the array

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you are just adding the elements up and dividing by the length of the range

neat scroll Sep 28, 2023, 6:49 AM

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compact salmon you shouldn't need to change the array

should or shouldnt idk if im understanding this right

compact salmon Sep 28, 2023, 6:50 AM

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shouldn't mb

neat scroll Sep 28, 2023, 6:50 AM

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okok yeah the second sentence made it sound like that lmao

neat scroll Sep 28, 2023, 6:50 AM

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compact salmon you are just adding the elements up and dividing by the length of the range

i think thats what i thought it was doing

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but

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yea thats def not whats going on

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wait idk whats the problem

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when does it not work?

compact salmon Sep 28, 2023, 6:53 AM

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hollow smelt

where are you doing this operation in your code

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the average you are calculating is not the average of your indices, it's the average of your elements in the range

neat scroll Sep 28, 2023, 6:54 AM

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holdup lemme use a calculator my brain is dying

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wait then why is it printing the write answers if the math is wrong

compact salmon Sep 28, 2023, 6:55 AM

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Did you try it with other input?

neat scroll Sep 28, 2023, 6:56 AM

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if i divide it by length right?

compact salmon Sep 28, 2023, 6:56 AM

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Most likely because your array sorted

neat scroll Sep 28, 2023, 6:56 AM

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i get 1.125

compact salmon Sep 28, 2023, 6:57 AM

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Yeah nvm, if you're dividing by the length it should be wrong. You might be getting lucky with your input

neat scroll Sep 28, 2023, 6:57 AM

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idk wtf is going on anymore

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lmao

compact salmon Sep 28, 2023, 6:57 AM

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Do you understand the difference between an element and its index?

compact salmon Sep 28, 2023, 6:58 AM

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neat scroll if i divide it by length right?

You are finding the average of the indices here

neat scroll Sep 28, 2023, 6:58 AM

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element is the literal number?

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and index is the location of the array

compact salmon Sep 28, 2023, 6:58 AM

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Yeah but you want the average of the elements in the array starting at indexStart to endIndex

neat scroll Sep 28, 2023, 6:58 AM

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compact salmon You are finding the average of the indices here

but im just finding range?

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isnt that just x + y /2

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wait idek what im finding anymore

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range is the middle number between

compact salmon Sep 28, 2023, 7:00 AM

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The range is the difference between the end and the start of a set of elements

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Median would be the middle number

neat scroll Sep 28, 2023, 7:02 AM

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well shit idk

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wtf am i calculating then

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ill ask the teacher but right now its 1am and i gotta get up early for school so thank u a bunch for your help, ill ask again if im still stuck on this tmrw

strong elkBOT Sep 28, 2023, 7:04 AM

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neat scroll ill ask the teacher but right now its 1am and i gotta get up early for school so...

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#How do I use try catch to catch an array out of bounds exception?