problems with saving data to arraylist

Programming Questions

mataarsak

problems with saving data to arraylist

in Programming Questions • 1 year ago

I receive udp data in this method , I save the data into an array-list but because I have a loop in every iteration the content of arraylist changed , and it does not save all of the data that comes. I don't know how should I delete and change the main loop .

Is there any other way to add new items to array list without deleting the items that saved there from the last iteration ?

void receive(byte[] data, String HOST_IP, int PORT_RX) {
receivedFromUDP ="";
for (int i = 0; i < data.length; i++) {
receivedFromUDP += str(data[i]) + " ";
int j = 0 ;
while ( j<data.length ) {
if ( data[2*j+2] >= 0 ) {
float[] bin2 = new float[] {
(unbinary(binary(data[2*j+3])+binary(data[2*j+2])+binary(data[2*j+1])+binary(data[2*j])))
};
balls.add(unbinary(binary(data[2*j+3])+binary(data[2*j+2])+binary(data[2*j+1])+binary(data[2*j])));
println("array list is" + balls);
}
}
j = j + 2;
}
}
}

Replies(3)

PhiLho

Re: problems with saving data to arraylist

1 year ago

You don't delete any data from the array list in the code snippet you show.
Perhaps you create a new array list before each call? Then initialize it only once, eg. in setup().

mataarsak

Re: Re: problems with saving data to arraylist

1 year ago

I create a new array list in setup and then initialize that there in my receive method as you can see in my code.

I add a line to print arraylist : println("arraylist:"+ balls)

and it prints like this :

arraylist: [44, 0.4 , ...]

arraylist: [3.2,6.7, ...]

it seems that it save many items in one elements of the array list because the packets receive is itself an array, how can I separate them and store each Item in one cell ?

PhiLho

Re: problems with saving data to arraylist

1 year ago

No, that's the way array lists are printed out.
See:

ArrayList a = new ArrayList();
a.add(5);
a.add(42);
println(a);

Top Reply