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Update lists with objects part
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</sample-output>

<programming-exercise name='Items' tmcname='part04-Part04_17.Items'>
<programming-exercise name='Items'>

Implement the class `Items` described here. **NB!** Don't modify the class `Item`.

Expand All @@ -228,257 +228,3 @@ Collar (created at: 06.07.2018 12:34:57)
</sample-output>

</programming-exercise>

## Multiple constructor parameters

If the constructor demands more than one parameter, you can query the user for more information. Let's assume we have the following constructor for the class `Person`.

```java
public class Person {

private String name;
private int age;
private int weight;
private int height;

public Person(String name, int age) {
this.name = name;
this.age = age;
this.weight = 0;
this.height = 0;
}

// methods
}
```

In this case, an object is created by calling the two-parameter constructor.

If we want to query the user for this kind of object, they must be asked for each parameter separately. In the example below, name and age parameters are asked separately from the user. Entering an empty name will end the reading part.

The persons are printed after they have been read.

```java
Scanner scanner = new Scanner(System.in);
List<Person> persons = new ArrayList<>();

// Read person information from the user
while (true) {
System.out.print("Enter name, empty will end: ");
String name = scanner.nextLine();
if (name.isEmpty()) {
break;
}

System.out.print("Enter the age of the person " + name + ": ");

int age = Integer.valueOf(scanner.nextLine());

// We add a new person to the list.
// The person's name and age were decided by the user
persons.add(new Person(name, age));
}

// We'll print the number of the inputted persons, and the persons themselves
System.out.println();
System.out.println("Total number of persons: " + persons.size());
System.out.println("Persons: ");

for (Person person: persons) {
System.out.println(person);
}
```

<sample-output>

Enter name, empty will end: **Grace Hopper**
Enter the age of the person Grace Hopper: **85**
Enter name, empty will end:

Total number of persons: 1
Persons:
Grace Hopper, age 85 years

</sample-output>

<programming-exercise name='Personal information' tmcname='part04-Part04_18.PersonalInformation'>

The program described here should be implemented in the class `PersonalInformationCollection`. **NB!** Do not modify the class `PersonalInformation`.

After the user has entered the last set of details (they enter an empty first name), exit the repeat statement.

Then print the collected personal information so that each entered object is printed in the following format: first and last names separated by a space (you don't print the identification number). An example of the working program is given below:

<sample-output>

First name: **Jean**
Last name: **Bartik**
Identification number: **271224**
First name: **Betty**
Last name: **Holberton**
Identification number: **070317**
First name:

Jean Bartik
Betty Holberton

</sample-output>

</programming-exercise>

<text-box type="info" name="Reading input in a specific format">

In the example and exercise below, the required information was entered line by line. By no means is it impossible to ask for input in a specific format, e.g. separated by a comma.

If the name and age were separated by a comma, the program could work in the following manner.

```java
Scanner scanner = new Scanner(System.in);
List<Person> persons = new ArrayList<>();

// Read person information from the user
System.out.println("Enter the person details separated by a comma, e.g.: Randall,2");
while (true) {
System.out.print("Enter the details, empty will stop: ");
String details = scanner.nextLine();
if (details.isEmpty()) {
break;
}

String[] parts = details.split(",");
String name = parts[0];
int age = Integer.valueOf(parts[1]);
persons.add(new Person(name, age));
}

// Print the number of the entered persons, and the persons themselves
System.out.println();
System.out.println("Total number of persons: " + persons.size());
System.out.println("Persons: ");

for (Person person: persons) {
System.out.println(person);
}
```

<sample-output>

Enter the person details separated by a comma, e.g.: Randall,2
Enter the details, empty will stop: **Leevi,2**
Enter the details, empty will stop: **Anton,2**
Enter the details, empty will stop: **Sylvi,0**
Enter the details, empty will stop:

Total number of persons: 3
Persons:
Leevi, age 2 years
Anton, age 2 years
Sylvi, age 0 years

</sample-output>

</text-box>


## Filtered printing from the list

You can also examine the objects on the list as you go through it. In the example below, we first ask the user for an age restriction, after which we print all the objects whose age is at least the number given by the user.

```java
// Assume we have a 'persons' list
// that consists of person objects

System.out.print("What is the age limit? ");
int ageLimit = Integer.valueOf(scanner.nextLine());

for (Person person: persons) {
if (person.getAge() >= ageLimit) {
System.out.println(person);
}
}
```

<programming-exercise name='Television programs' tmcname='part04-Part04_19.TelevisionPrograms'>

In the exercise template there is a ready-made class TelevisionProgram, representing a television program. The class has object variables name and duration, a constructor, and a few methods.

Implement a program that begins by reading television programs from the user. When the user inputs an empty string as the name of the program, the program stops reading programs.

After this the user is queried for a maximum duration. Once the maximum is given, the program proceeds to list all the programs whose duration is smaller or equal to the specified maximum duration.

<sample-output>

Name: **Rick and Morty**
Duration: **25**
Name: **Two and a Half Men**
Duration: **30**
Name: **Love it or list it**
Duration: **60**
Name: **House**
Duration: **60**

Program's maximum duration? **30**
Rick and Morty, 25 minutes
Two and a Half Men, 30 minutes

</sample-output>

</programming-exercise>

<programming-exercise name='Books' tmcname='part04-Part04_20.Books'>

Write a program that first reads book information from the user. The details to be asked for each book include the title, the number of pages and the publication year. Entering an empty string as the name of the book ends the reading process.

After this the user is asked for what is to be printed. If the user inputs "everything", all the details are printed: the book titles, the numbers of pages and the publication years. However, if the user enters the string "name", only the book titles are printed.

It is probably worthwhile to implement a class called `Book` to represent a book. There are two points in total available for this exercise.

<sample-output>

Title: **To Kill a Mockingbird**
Pages: **281**
Publication year: **1960**
Title: **A Brief History of Time**
Pages: **256**
Publication year: **1988**
Title: **Beautiful Code**
Pages: **593**
Publication year: **2007**
Title: **The Name of the Wind**
Pages: **662**
Publication year: **2007**
Title:

What information will be printed? **everything**
To Kill a Mockingbird, 281 pages, 1960
A Brief History of Time, 256 pages, 1988
Beautiful Code, 593 pages, 2007
The Name of the Wind, 662 pages, 2007

</sample-output>

<sample-output>

Title: **To Kill a Mockingbird**
Pages: **281**
Publication year: **1960**
Title: **A Brief History of Time**
Pages: **256**
Publication year: **1988**
Title: **Beautiful Code**
Pages: **593**
Publication year: **2007**
Title: **The Name of the Wind**
Pages: **662**
Publication year: **2007**
Title:

What information will be printed? **name**
To Kill a Mockingbird
A Brief History of Time
Beautiful Code
The Name of the Wind

</sample-output>

</programming-exercise>

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