/**
* Returns a formatted string version of this set Examples: If set contains "a" and "b", this
* method should return the string "{a, b}". If the set is empty, this method should return the
* string "{}".
*/
public String toString() {
String result = "{";
if (size() > 0) result += data.get(0);
for (int i = 1; i < data.size(); i++) result += ", " + data.get(i);
return result + "}";
}
/**
* Removes e from the set, and throws an IllegalArgumentException if e is null
*
* @param e
*/
public void remove(String e) {
if (e == null) throw new IllegalArgumentException();
for (int i = 0; i < data.size(); i++) {
if (data.get(i).equals(e)) {
data.remove(i);
break;
}
}
}
/**
* Indicates whether the set contains e, and throws an IllegalArgumentException if e is null.
*
* @param e
* @return true if the set contains e
*/
public boolean contains(String e) {
if (e == null) throw new IllegalArgumentException();
boolean exist = false;
for (int i = 0; i < data.size(); i++) {
if (data.get(i).equals(e)) {
exist = true;
}
}
return exist;
}
/**
* Adds e to the set if there is not already an element in the set equal to e.Plus,throws an
* IllegalArgumentException if e is null
*
* @param e
*/
public void insert(String e) {
if (e == null) throw new IllegalArgumentException();
// don't add the string if it already exists
if (contains(e)) {
return;
} else {
data.add(e);
}
}
// Returns the number of strings in the set
public int size() {
return data.size();
}
