The subnet calculator helps you design networks by taking an IP address and network mask and returning information such as network, broadcast address, and host range.
One of a set of tools we're offering as a way of saying thank you for being a part of the community.
Set theSet = new HashSet()
1) Adding to the combo box should be like this:
instead of
yourCombo.add("a1");
you should write:
if ( !theSet.contains("a1") ) {
yourCombo.add("a1");
theSet.add("a1")
}
2) Removing
instead of
yourCombo.removeItem("a1")
you should write:
yourCombo.removeItem("a1")
theSet.remove("a1");