I've trying to figure out this exercise in the book Objects First with Java for a couple of hours, not managing to understand several aspects.
The exercise reads: Rewrite the printEndangered method in your project to use streams. Test. (To test this method, it may be easiest to write a test method that creates an ArrayList of animal names and calls the printEndangered method with it.)
/**
* Print a list of the types of animal considered to be endangered.
* @param animalNames A list of animals names.
* @param dangerThreshold Counts less-than or equal-to to this level
* are considered to be dangerous.
*/
public void printEndangered(ArrayList<String> animalNames,
int dangerThreshold)
{
for(String animal : animalNames) {
if(getCount(animal) <= dangerThreshold) {
System.out.println(animal + " is endangered.");
}
}
}
At the start of this chapter I was asked to test out the methods of this class, but the printEndangered-method I didn't get to work. I did not understand what to put in the parameter field of the ArrayList-parameter, and so now I can't manage to write this method.
How do you use an ArrayList as a parameter? What do they mean by write a test method that creates an ArrayList of animal names? How will I go forth writing this method?
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