Java Code For Creating a Set

A set is a collection that holds unique values. Adding a value that's already in the set has no effect. // Create the set

Set set = new HashSet();

// Add elements to the set
set.add("a");
set.add("b");
set.add("c");

// Remove elements from the set
set.remove("c");

// Get number of elements in set
int size = set.size(); // 2

// Adding an element that already exists in the set has no effect
set.add("a");
size = set.size(); // 2

// Determining if an element is 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 containing the elements in the set (in this case a String array)
String[] array = (String[])set.toArray(new String[set.size()]);