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Array Help (Read 1544 times)

IceKat

Array Help
May 28^th, 2010, 7:46am

Hi,

Yet another question.

I have a two dimensional array declared as:

int coords[][] = {{0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18},{0,1,2,3,4,5,6,7,8,9,10,11,12,
13,14,15,16,17,18}};

Problem is that when I declare:

coords[1][1] = "spec1"; - this works fine

but...
coords[2][2] = "spec2"; - doesn't work

...the second one gives me the error:

Exception in thread "Animation Thread" java.lang.ArrayIndexOutOfBoundsException: 2
at assignment3.load_level(assignment3.java:98)
at assignment3.select_pic(assignment3.java:235)
at assignment3.mouseClicked(assignment3.java:64)
at processing.core.PApplet.handleMouseEvent(PApplet.java:1614)
at processing.core.PApplet.dequeueMouseEvents(PApplet.java:1544)
at processing.core.PApplet.handleDraw(PApplet.java:1436)
at processing.core.PApplet.run(PApplet.java:1327)
at java.lang.Thread.run(Thread.java:619)

I want to go up to declaring that....
coords[18][18] = "spec18"; - and everything in between.

Any help would be appreciated. I'm not good with arrays, let alone double dimension arrays. Did I declare it wrong?

IceKat.

blindfish

Re: Array Help
Reply #1 - May 28^th, 2010, 7:56am

IceKat wrote on May 28^th, 2010, 7:46am:

I have a two dimensional array declared as:

int coords[][] = {{0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18},{0,1,2,3,4,5,6,7,8,9,10,11,12,
13,14,15,16,17,18}};

Problem is that when I declare:

coords[1][1] = "spec1"; - this works fine

but...
coords[2][2] = "spec2"; - doesn't work

...the second one gives me the error:

<snip>

Array indices start at 0. Your 2d array currently contains only two sub-arrays with 19 elements each.

coords[2][2] references the third item in a non-existent third sub-array...

Where is the what if the what is in why?

IceKat YaBB Newbies Offline Posts: 7	Re: Array Help Reply #2 - May 28^th, 2010, 8:02am So how should I declare it so I can have.... coords[2][2] = "spec2"; ??? And whilst I'm on here I may as well ask...how do I pull "spec2" out again? I appreciate the help, like I said I'm new to arrays - particularly in processing. IceKat.

PhiLho

Re: Array Help
Reply #3 - May 28^th, 2010, 8:28am

IceKat wrote on May 28^th, 2010, 7:46am:

coords[1][1] = "spec1"; - this works fine

I doubt it... Wink

You assign a string to an array of ints!

There is a simpler way to create an array:
Code:

// Declare and create a double dimension array
int[][] coords = new int[20][20];
// Now, you can populate your array
for (int i = 0; i < coords.length; i++)
{
  coords[i][i] = i;
}

Rapatsk1

Re: Array Help
Reply #4 - May 28^th, 2010, 8:55am

IceKat wrote on May 28^th, 2010, 8:02am:

So how should I declare it so I can have....

coords[2][2] = "spec2";

? And whilst I'm on here I may as well ask...how do I pull "spec2" out again

I appreciate the help, like I said I'm new to arrays - particularly in processing.

IceKat.

Hehe and what you meant by coords[1][1] is in fact coords[0][0].

But I guess these "spec" strings are meant to be variables to make the data easier to understand

do it like this:

Code:

int spec1 = coords[0][0];

I often do something similar:

Code:

for(int j = 0; j < points_3d.length; j++) {

  rotateY(j*TWO_PI/float(points_3d.length));

  for(int i = 0; i < points_3d[j].length; i++) {

    float mx = modelX(points_3d[j][i].x, points_3d[j][i].y, 0);
    float my = modelY(points_3d[j][i].x, points_3d[j][i].y, 0);
    float mz = modelZ(points_3d[j][i].x, points_3d[j][i].y, 0);

    println("("+mx+", "+my+", "+mz+")");

  }

}

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