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This Java tip illustrates a method of creating a Set. A set is a group of unique elements.
If an element is already present in a set it cannot be added in the set.
// Create a set
Set set = new HashSet();
// Add some elements to the set
set.add("a");
set.add("b");
set.add("c");
// Remove elements from the set
set.remove("c");
// Retrieve number of elements in the set
int size = set.size(); // 2
// Adding an element that already exists has no effect
set.add("a");
size = set.size(); // 2
// Identifying the presence of an element in the set
boolean b = set.contains("a"); // true
b = set.contains("c"); // false
// Iterating over the elements in the set
Iterator it = set.iterator();
while (it.hasNext()) {
// Get element
Object element = it.next();
}
// Create an array (ex. string) of all elements in the set
String[] array = (String[])set.toArray(new String[set.size()]);
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