The following java code will be written for the prescribed
<u>Explanation:</u>
import java.util.*;
class UserName{
ArrayList<String> possibleNames;
UserName(String firstName, String lastName){
if(this.isValidName(firstName) && this.isValidName(lastName)){
possibleNames = new ArrayList<String>();
for(int i=1;i<firstName.length()+1;i++){
possibleNames.add(lastName+firstName.substring(0,i));
}
}else{
System.out.println("firstName and lastName must contain letters only.");
}
}
public boolean isUsed(String name, String[] arr){
for(int i=0;i<arr.length;i++){
if(name.equals(arr[i]))
return true;
}
return false;
}
public void setAvailableUserNames(String[] usedNames){
String[] names = new String[this.possibleNames.size()];
names = this.possibleNames.toArray(names);
for(int i=0;i<usedNames.length;i++){
if(isUsed(usedNames[i],names)){
int index = this.possibleNames.indexOf(usedNames[i]);
this.possibleNames.remove(index);
names = new String[this.possibleNames.size()];
names = this.possibleNames.toArray(names);
}
}
}
public boolean isValidName(String str){
if(str.length()==0) return false;
for(int i=0;i<str.length();i++){
if(str.charAt(i)<'a'||str.charAt(i)>'z' && (str.charAt(i)<'A' || str.charAt(i)>'Z'))
return false;
}
return true;
}
public static void main(String[] args) {
UserName person1 = new UserName("john","smith");
System.out.println(person1.possibleNames);
String[] used = {"harta","hartm","harty"};
UserName person2 = new UserName("mary","hart");
System.out.println("possibleNames before removing: "+person2.possibleNames);
person2.setAvailableUserNames(used);
System.out.println("possibleNames after removing: "+person2.possibleNames);
}
}
