Class Syntax

The syntax for creating a class is quite simple. Let's take a look at an example with the class Person:

Person.java


              123
            
class Person {

}

This is all it takes to create a class. However, it will be useless to us if it's empty. Therefore, we should add fields to it. Let's assume that our person has a name, gender, and age:

Person.java


              12345
            
class Person {
    String name;
    String gender;
    int age;
}

And now, let's write a method that allows our Person to report their name and age:

Person.java


              123456789
            
class Person {
    String name;
    String gender;
    int age;
    
    void introduce() {
        System.out.println("Hi, my name is " + name + " and I am " + age + " years old!");
    }
}

Uppgift

Swipe to start coding

Alice wants to find a friend within a specific age range (25 - 30, inclusive). You need to write a program that checks whether Bob meets Alice's criteria. If Bob's age falls within the specified range, the program should return true; otherwise, it should return false.

In the main method, you need to pass the correct object as the first parameter to the findFriend method.
In the findFriend method, compare the age of the passed object with the specified age range (25 - 30).
If the object falls within the age range, return true; otherwise, return false.
To display the result on the screen, use the foundFriend variable, which stores the result of the search.

Lösning

Var allt tydligt?

Tack för dina kommentarer!

Avsnitt 1. Kapitel 4

single

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Class Syntax

The syntax for creating a class is quite simple. Let's take a look at an example with the class Person:

Person.java


              123
            
class Person {

}

This is all it takes to create a class. However, it will be useless to us if it's empty. Therefore, we should add fields to it. Let's assume that our person has a name, gender, and age:

Person.java


              12345
            
class Person {
    String name;
    String gender;
    int age;
}

And now, let's write a method that allows our Person to report their name and age:

Person.java


              123456789
            
class Person {
    String name;
    String gender;
    int age;
    
    void introduce() {
        System.out.println("Hi, my name is " + name + " and I am " + age + " years old!");
    }
}

Uppgift

Swipe to start coding

In the main method, you need to pass the correct object as the first parameter to the findFriend method.
In the findFriend method, compare the age of the passed object with the specified age range (25 - 30).
If the object falls within the age range, return true; otherwise, return false.
To display the result on the screen, use the foundFriend variable, which stores the result of the search.

Lösning

Byt till skrivbordet för praktisk övningFortsätt där du är med ett av alternativen nedan

Var allt tydligt?

Tack för dina kommentarer!

Avsnitt 1. Kapitel 4

single

Class Creation

Class Syntax

Lösning

Class Creation

Class Syntax

Lösning