java - Instantiating array but keep getting IndexOutOfBounds Exception -


i'm trying tally count array keep set of 50 choices there 3 options each choice. count array should have 150 elements, per instructor (3 x 50 = 150). keep getting indexoutofbounds exception @ line 55 (index = thischoice.get(i)). i'm thinking must have how (or where?) i'm instantiating count array @ 

line 50: int[] count = new int[students.get(0).getchoices().size()*3]

because rest of code came instructor , presumably correct. ideas on sending out of bounds?

public class p1driver {  public static void main(string[] args) throws ioexception{      arraylist<students> students = new arraylist<students>();     arraylist<string> choices = new arraylist<string>();     scanner scan1 = new scanner(new file("choices.txt"));     scanner scan2 = new scanner(new file("eitheror.csv"));      // scan first file.     int choicesindex = 0;     while(scan1.hasnextline()){         string line = scan1.nextline();         choices.add(line);         choicesindex++;     }     scan1.close();      // scan second file.     int studentindex = 0;     while(scan2.hasnextline()){         string line = scan2.nextline();         string [] splits = line.split(",");           students.add(new students(splits[0]));          for(int = 1; < splits.length; i++){             students.get(studentindex).addchoices(integer.parseint(splits[i]));         }         studentindex++;     }     scan2.close();      // instantiate , add count array.     int index, countindex;     arraylist<integer> thischoice;     int[] count = new int[students.get(0).getchoices().size()*3];     for(int = 0; < students.size(); i++){         countindex = 1;         thischoice = students.get(i).getchoices();         for(int j = 0; j < thischoice.size(); j++){             index = thischoice.get(i);             count[countindex + index] = count[countindex + index] + 1;             countindex+=3;         }     }      // display data.     countindex = 1;     for(int = 0; < choices.size(); i+=2){         system.out.println(choices.get(i) + count[countindex] + choices.get(i+1) + count[countindex+1] + " invalid: " + count[countindex-1]);         countindex+=3;     }

hi please check second nested loop, should j instead of i . haven't used int j in loop.

 (int = 0; < students.size(); i++) {         countindex = 1;         thischoice = students.get(i).getchoices();         (int j = 0; j < thischoice.size(); j++) {             index = thischoice.get(j);             count[countindex + index] = count[countindex + index] + 1;             countindex += 3;         }     }

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