Question

The UML diagram for an Instantiable class Person is shown below:

Write an application program to create 5 person objects, with appropriate data, using a suitable array.
Using the information entered for the 5 objects, write methods to:
• count the number of females in the array
• count the number of people aged over 25
• find the average age of all males
• find the average age of all people

Person

-name:String
-age:int
-gender:char

+Person()
+Person(String, int, char)
+setName(String):void
+setAge(int):void
+setGender(char):void
+getName():String
+getAge():int
+getGender():char
+toString():String

Answer 1

public class PersonApp {
public static void main(String[] args) {
Person[] persons = new Person[5];
Person person1 = new Person("Bob", 25, 'm');
Person person2 = new Person("Alica", 30, 'w');
Person person3 = new Person("Cris", 22, 'm');
Person person4 = new Person("Natalie", 19, 'w');
Person person5 = new Person("Anna", 34, 'w');
persons[0] = person1;
persons[1] = person2;
persons[2] = person3;
persons[3] = person4;
persons[4] = person5;
System.out.println("Female number = " + femaleNum(persons));
System.out.println("Aged over 25 number = " + under25Num(persons));
System.out.println("Average male age = " + averageMaleAge(persons));
System.out.println("Average people age = " + averageAllAge(persons));
}
/**
* count the number of females in the array
* @param persons
* @return the count
*/
public static int femaleNum(Person[] persons) {
int count = 0;
for (Person p : persons) {
if (p.getGender() == 'w') {
count++;
}
}
return count;
}
/**
* count the number of people aged over 25
* @param persons
* @return the count
*/
public static int under25Num(Person[] persons) {
int count = 0;
for (Person p : persons) {
if (p.getAge() > 25) {
count++;
}
}
return count;
}
/**
* find the average age of all males
* @param persons
* @return the count
*/
public static int averageMaleAge(Person[] persons) {
int count = 0, sum = 0;
for (Person p : persons) {
if (p.getGender() == 'm') {
count++;
sum += p.getAge();
}
}
return sum / count;
}
/**
* find the average age of all people
* @param persons
* @return the count
*/
public static int averageAllAge(Person[] persons) {
int sum = 0;
for (Person p : persons) {
sum += p.getAge();
}
int count = persons.length;
return sum / count;
}
/**
* Person class
*/
public class Person {
private String name;
private int age;
private char gender;
/**
* Default constructor
*/
public Person() {
name = "";
age = 0;
gender = 'm';
}
/**
* Constructor
* @param name
* @param age
* @param gender
*/
public Person(String name, int age, char gender) {
this.name = name;
this.age = age;
this.gender = gender;
}
/**
* Fields getters and setters
*/
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public char getGender() {
return gender;
}
public void setGender(char gender) {
this.gender = gender;
}
@Override
public String toString() {
return "Name: " + getName() + " age: " + getAge() + " gender: " + getGender();
}
}