Indexing an ArrayList

[Doegon]

Hi guys how does one index an object with a collection in an ArrayList,the code i used reports an error."expected is an array and found is an array list" and the possible loss of precision error.this is the code

while(inFile.ha sNext())
{
for(Worker worka : badiri){ //fills up the collection with worker objects
badiri.add(new Worker(workerNa me,salaryRate)) ;
}
badiri.sort(); //sorts the collection


for(int j= 0; j< badiri.length;j ++){ //computes the sum of the salary rates all the workers
sum+= worka.getSalary Rate();
}

median = sum/badiri.length; //computes the median salary rate

//output

System.out.prin tln("Smallest Salary Rate= " + badiri[0].toString());
System.out.prin tln("Median Salary Rate= " + badiri[median].toString());
System.out.prin tln("Largest Salary Rate= " + badiri[badiri.length-1].toString());

}//close while loop #2

[Laharl]

At which lines do you get the errors? The output lines would give you an error, since unlike C++ vectors, ArrayLists do not use the [] to access members. You use .get() instead.

[Doegon]

Thanks a lot man,the get() method worked but i still get an error on sorting the ArrayList.
i used the method call of
Collections.sor t(variablename) ;
it doesn't seem to recognize the function.

[Laharl]

You have to import java.util.Colle ctions to use that. You will get a warning that it's an unsafe call for reason's I'm not entirely sure of...You /should/ be able to ignore that.

[Doegon]

i have imported the java.util.*; class and it seems like no effect is shown the erro is still there.

[JosAH]

i have imported the java.util.*; class and it seems like no effect is shown the erro is still there.

If you want accurate help be accurate yourself: please show us the exact error
diagnostic message for complete information. (that includes the line number where
the error was found) and a bit of relevant code. The Collections class exists since
Java 1.2 so it's definitely there including its methods.

kind regards,

Jos

[Doegon]

here is the code and below is the error report i hpoe it helps


ArrayList<Worke r> badiri = new ArrayList<Worke r>(); //create a collection of the workers

double sum = 0.0;

while(inFile.ha sNext())
{
for(Worker worka : badiri){ //fills up the collection with worker objects
badiri.add(new Worker(workerNa me,salaryRate)) ;
}
Collections.sor t(badiri); //sorts the collection


for(Worker worky : badiri){ //computes the sum of the salary rates all the workers
sum+= worky.getSalary Rate();
}

for(Worker mmereki : badiri){
if(sum/badiri.size() == mmereki.getSala ryRate()){ //prints the worker with median salary rate
System.out.prin tln(mmereki.toS tring());
}
}

//output

System.out.prin tln("Smallest Salary Rate= " + badiri.get(0).t oString());
// System.out.prin tln("Median Salary Rate= " + badiri.get(medi an).toString()) ;
System.out.prin tln("Largest Salary Rate= " + badiri.get(badi ri.size()).toSt ring());

}//close while loop #2

inFile.close();
outFile.close() ;
}



WorkerTester.ja va:10: cannot find symbol
symbol : method sort(java.util. ArrayList<Worke r>)
location: class java.util.Colle ctions
Collections.sor t(badiri); //sorts the collection

[JosAH]

WorkerTester.ja va:10: cannot find symbol
symbol : method sort(java.util. ArrayList<Worke r>)
location: class java.util.Colle ctions
Collections.sor t(badiri); //sorts the collection

Read the API docs for that method: it needs something that is a Comparable,
i.e. it can't sort just any type of object. Your Worker class doesn't implement that
Comparable interface.

kind regards,

Jos