Answer:
Here is the program for the given question
Explanation:
class StringSet
{
ArrayList<String> arraylist; //a reference variable of ArrayList of generic type String
//A no argument constructor.
public StringSet()
{
arraylist=new ArrayList<String>(); //instantiating the ArrayList object
}
//A mutator that adds a String newStr to the StringSet object.
void add(String newStr)
{
arraylist.add(newStr); // add(String) method to add string to the arraylist
}
//An accessor that returns the number of String objects that have been added to this StringSet object.
int size()
{
return arraylist.size(); // size() method which gives the number of elements in the list
}
//An accessor that returns the total number of characters in all of the Strings that have been added to this StringSet object.
int numChars()
{
int sum = 0;
for(String str:arraylist) //for-each loop; can be read as for each string in arraylist
{
sum+=str.length();
}
return sum;
}
//An accessor that returns the number of Strings in the StringSet object that have exactly len characters.
int countStrings(int len)
{
int count = 0;
for(String str:arraylist)
{
if(str.length() == len)
count++;
}
return count;
}
}
