How to execute contain operation in sequences?

Question

Hi,I am confused about sequences,it seems java.util.Collection more convenient,so why need sequences.
and how can I do a contain operation on sequences?if use indexof operator,how to determin object equals?how to implements equals method in javafx object?

Answer 1

One way to determine whether or not a Sequence contains an element is to implement a Comparator (or have the element implement Comparable) and use the javafx.util.Sequences.binarySearch function.
I don't have access to a compiler at the moment, but something like this should work:
import javafx.util.Sequences;
var strings: String[] = [
        "Hello",
        "World",
        "Goodbye"
//Sequence needs to be sorted for us to be able to determine whether or not it contains a given string with a binary search. String already implements Comparable, so we do not need to use a comparator.
strings = Sequences.sort(strings);
//Now determine whether or not this sequence contains the specified string.
var containsString: Boolean = (Sequences.binarySearch(strings, "Hello") != -1); //This should return true.I haven't tried overriding equals, but I've overridden toString() just fine, so you can probably do that in a similar way:
public class MidiInstrument {
    public-init var name: String;
    public-init var bank: Integer;
    public-init var program: Integer;
     * Overrides toString to ensure that the ChoiceBox used to choose an instrument can display this item as a string.
    public override function toString(): String {
        return name;
}