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Index › Programming Questions & Help › Syntax Questions › difficulties with arrays
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difficulties with arrays (Read 478 times)
pieterCoussement
difficulties with arrays
Dec 27th, 2007, 8:43pm  
Hi all,
I'm doing my first babysteps with processing and am trying to build an application to drive the 'grote grijze muizenshow' a quiz thingy me and my GF came up with for new years eve.

I have this database with questions and answers out of wich I have to choose random questions. So it's an array like the example I found on the site. I have a random function
r=ceil(random(firstName.lenght))-1; to get my questions.
But I want each random function to go into an array, so I can check if the question (=randomNumber) has already been chosen.
But I get a really strange array if I print it(~2mia/c  lijst[I@c7cb793)

here is the code so far (remember babysteps ;-)

String[]firstName={"jan","bob","mia","pieter","marijke","joris","ivan","bram","veerle","
ellen","kim"};
String[]lastName={"a","b","c","d","e","f","g","h","i","j","k","l"};
int[]lijst=new int[0];
int sielR=ceil(0);
int mouseCheck=0;

void draw(){
}
void mousePressed() {
 int r=ceil(random(firstName.length))-1;
 lijst=append(lijst,r);
 print(r);
 print(firstName[r]+"/");
 print(lastName[r]+"  ");
 print("lijst"+lijst);
 mouseCheck ++;
 print(mouseCheck);
}

hope someone can give me some pointers
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antiplastik
Re: difficulties with arrays
Reply #1 - Dec 28th, 2007, 4:23pm  
Quote:
But I get a really strange array if I print it(~2mia/c  lijst[I@c7cb793)

yes, because you can't use println() with an array! you should try to replace the line print("lijst"+lijst); with the following code :

Code:
print("lijst : [");
for (int i = 0; i < lijst.length; i++) {
  print(lijst[i]);
  if (i < lijst.length - 1) print(", ");
}
println("]");
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extrapixel
Re: difficulties with arrays
Reply #2 - Dec 30th, 2007, 2:53am  
to be precise, processings println() has array printing built in. But you must use println (not just print()), and only pass the list to it. so, replace

print("lijst"+lijst);

with

println("lijst:");
println(lijst);
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http://www.extrapixel.ch
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pieterCoussement
Re: difficulties with arrays
Reply #3 - Dec 30th, 2007, 1:23pm  
Thanx guys, it's a bit hard for me to see what I'm doing but while printing it's ok.

Now for the next part I want to shuffle an array, by choosing a random element in the first array and append() it to the next while removing it from the first.
Then generate a random(firstArray.length) element from the first again and append it to the next when the firstArray.length==0 saving the file and exiting the programm.
The thing is I can't seem to get the remove part which I copied from another script.
I know i should be learning this diffrently but the great grey mouse show (the quiz) is tomorrow so I'm begging for your help!

here's the script:


float rand =0;
int keuze= 0;

String[] lines;
String[] shuffleArray={"Vraag en antwoord"};
int recordCount;
PFont body;
int num = 1; // Display this many entries on each screen.
int startingEntry = 0;  // Display from this entry number

void setup()
{
 size(200, 200);
 fill(255);
}
void draw(){

 
 lines = loadStrings("kwisvragen.txt");
 if(lines.length!=0){
   int r=floor(random(lines.length));
   shuffleArray=append(shuffleArray,lines[r]);
   print(r+"   ");
   String[] lines(String[]vals, int index){
     vals=concat(subset(vals,0,index),subset(vals,index+1));
     return vals;
   }
 }else{
   println(shuffleArray);
   saveStrings("shuffle.txt",lines);
   exit();
 
}
}

   
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pieterCoussement
Re: difficulties with arrays
Reply #4 - Dec 31st, 2007, 7:02am  
to answer my own questions here is the script that worx (and then crashes processing) hehe:
thx everyone for helping me through the codingforest

String[] naam;
String[] verzamel={"vraag en antwoord"};
void setup(){
 naam = loadStrings("kwisvragen.txt");
}

void draw(){

 for(int i=0;i%100<=0;i++){
   if(i==0){
     if(naam.length>0){
       int r= ceil(random(naam.length-1));
       verzamel=append(verzamel,naam[r]);
       print(r);
       naam=concat(subset(naam,0,r),subset(naam,r+1));
       println(naam);
       
     }else{
       saveStrings("shuffle.txt",verzamel);
       exit();
     }
   }
 }
}
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antiplastik
Re: difficulties with arrays
Reply #5 - Dec 31st, 2007, 7:40am  
Quote:
I know i should be learning this diffrently

Indeed, I think it would have been easier to work with Java Collections, which provide lots of useful built-in methods :
http://java.sun.com/j2se/1.4.2/docs/api/java/util/Collection.html
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