Array accessed out of bounds? What does that mean?

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dab

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Posted: 29th Jul 2005 16:46

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What does array accessed out of bounds. For some reason it says that everytime I try to make it equal to the y point in the screen.

if you need code just ask but what I am doing is this:

+ Code Snippet

if getyonce=1
  y2(numdot#)=y
  getyonce=2
endif

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BatVink

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Posted: 29th Jul 2005 17:19

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If an array has 10 elements, and you try to access element 11, you will get this message.

ARRAY COUNT() will tell you how many elements you have, if you have lost track.

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Metrion

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Posted: 29th Jul 2005 17:45

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Another thing is that if you access

array(0)

this is a common mistake.

If practice makes perfect and nobody is perfect, then why practice?

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dab

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Posted: 30th Jul 2005 03:07 Edited at: 30th Jul 2005 03:18

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Well, I don't see what could be the problem. It couldn't be the array(0) thing but I'm going to check. And an element is the thing like this:
array(1,2,3,4,5,6,7,8,9,10,11)
right? IF so then thats not what the problem is.

edit: Uhh here's the source:

Rem * Title  : Shjp Test
Rem * Author : David B
Rem * Date   : today
sync on
hide mouse
nume=1
dim y2(nume)=y
img=1
load image "ship-up.bmp",1
load image "ship-down.bmp",2
load image "ship-left.bmp",3
load image "ship-right.bmp",4
for stars = 1 to 300
dim starx(stars)
dim stary(stars)
next stars

for star2 = 1 to 300 
starx(star2)=rnd(640)
stary(star2)=rnd(480)
next star2

white=rgb(255,255,255)
red=rgb(255,0,0)

y=400
x=320

bullettimer=0

do
cls

sprite 1,x,y,img

print bullettimer

if upkey()=1 
img=1
 y=y-5
endif

if downkey()=1
img=2
 y=y+5
endif

if leftkey()=1 
img=3
 x=x-5
endif

if rightkey()=1 
img=4
 x=x+5
endif

if spacekey()=1 then bullet=1

rem Here is the problem
rem here is the problem
rem  v  v  v  v  v  v  v  v (down)
if bullet=1
  inc nume,1
  inc bullettimer,1
	    if getyonce=0
            y2(nume)=y
          getyonce=1
       endif
  inc nume,1
       if getyonce=1 and bullettimer > 10
           y2(nume)=y
         getyonce=2
       endif
  inc nume,1
       if getyonce=2 and bullettimer > 20
           y2(nume)=y
         getyonce=3
       endif
  inc nume,1
       if getyonce=3 and bullettimer > 30
           y2(nume)=y
         getyonce=4
       endif
  inc nume,1
       if getyonce=4 and bullettimer > 40
           y2(nume)=y
         getyonce=5
       endif
     y2(nume)=y2(nume)-5
     ink red,0
	  dot x,y2(nume)
endif
  if bullettimer>25
    getyonce=0
  endif
  if bullettimer>70
       y2=y
    bullettimer=0
    bullet=0
endif

rem end of problem ^  ^  ^  ^  ^ (end of problem)

if y >=440 then y=440

if downkey()=0 and upkey()=0 and leftkey()=0 and rightkey()=0 then img=1

if x > 640 then x=5
if x <5 then x=640
if y <= 200
  if y <100
   y=y+5
 endif
endif

for star = 1 to 300
stary(star)=stary(star)+1

if stary(star)> 480
starx(star)=rnd(640)
stary(star)=1
endif
ink white,0
dot starx(star),stary(star)

next star

sync
loop

+ Code Snippet

Rem * Title  : Shjp Test
Rem * Author : David B
Rem * Date   : today
sync on
hide mouse
nume=1
dim y2(nume)=y
img=1
load image "ship-up.bmp",1
load image "ship-down.bmp",2
load image "ship-left.bmp",3
load image "ship-right.bmp",4
for stars = 1 to 300
dim starx(stars)
dim stary(stars)
next stars

for star2 = 1 to 300 
starx(star2)=rnd(640)
stary(star2)=rnd(480)
next star2

white=rgb(255,255,255)
red=rgb(255,0,0)

y=400
x=320

bullettimer=0

do
cls

sprite 1,x,y,img

print bullettimer

if upkey()=1 
img=1
 y=y-5
endif

if downkey()=1
img=2
 y=y+5
endif

if leftkey()=1 
img=3
 x=x-5
endif

if rightkey()=1 
img=4
 x=x+5
endif

if spacekey()=1 then bullet=1






rem Here is the problem
rem here is the problem
rem  v  v  v  v  v  v  v  v (down)
if bullet=1
  inc nume,1
  inc bullettimer,1
	    if getyonce=0
            y2(nume)=y
          getyonce=1
       endif
  inc nume,1
       if getyonce=1 and bullettimer > 10
           y2(nume)=y
         getyonce=2
       endif
  inc nume,1
       if getyonce=2 and bullettimer > 20
           y2(nume)=y
         getyonce=3
       endif
  inc nume,1
       if getyonce=3 and bullettimer > 30
           y2(nume)=y
         getyonce=4
       endif
  inc nume,1
       if getyonce=4 and bullettimer > 40
           y2(nume)=y
         getyonce=5
       endif
     y2(nume)=y2(nume)-5
     ink red,0
	  dot x,y2(nume)
endif
  if bullettimer>25
    getyonce=0
  endif
  if bullettimer>70
       y2=y
    bullettimer=0
    bullet=0
endif

rem end of problem ^  ^  ^  ^  ^ (end of problem)




if y >=440 then y=440


if downkey()=0 and upkey()=0 and leftkey()=0 and rightkey()=0 then img=1

if x > 640 then x=5
if x <5 then x=640
if y <= 200
  if y <100
   y=y+5
 endif
endif


for star = 1 to 300
stary(star)=stary(star)+1

if stary(star)> 480
starx(star)=rnd(640)
stary(star)=1
endif
ink white,0
dot starx(star),stary(star)

next star



sync
loop

Also, the bullets (which is what I'm having trouble with) isn't quite finished with. I just ran into this error and couldn't get rid of it.

So far though, thanks for your help!

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TDK

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Location: UK

Posted: 30th Jul 2005 08:36

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Accessing element 0 of an array is not a common mistake - it's there, so you can use it!

If you need an array to hold 4 values, you can use

DIM Arrayname(3)

Although arrays can be real or integer, element variables should always be integers.

y2#(numdot)=y#
y2(numdot)=y

are both OK, but

y2(numdot#)=y

is not.

In your code, you use

nume=1
dim y2(nume)=y

This means your array size is only 2 (elements 0 and 1). Once Nume gets to 2 then your error occurs because you told DB you only wanted an array to store two values.

What you need to do is DIMension the array to the biggest size you will need.

Try with

DIM y2(100)

or more if you know Nume is going to get bigger.

TDK_Man

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TDK

Retired Moderator

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Joined: 19th Nov 2002

Location: UK

Posted: 30th Jul 2005 08:42

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Oops - just noticed another problem...

You have

for stars = 1 to 300
dim starx(stars)
dim stary(stars)
next stars

this is wrong. What you are doing here is dimensioning both arrays 300 times - the first time with 1, then 2, then 3 and so on!

All you need is:

Dim starx(300)
Dim stary(300)

TDK_Man

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blanky

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Location: ./

Posted: 30th Jul 2005 20:09

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Yeah, what TDKMan said - You just declared your arrays 300 times over

Also, you CAN use element 0.

Syntax Error - Learn to type, you fool!

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dab

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Posted: 30th Jul 2005 21:22

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Oh OKay!! Thanks. I get it. Thank You!!

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blanky

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Posted: 30th Jul 2005 23:23

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Yay!

[Insert extremely witty comment here]

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DarkBASIC Discussion / Array accessed out of bounds? What does that mean?