JAVA · ОСНОВЫ · LESSON 20

Name upon creation

Designer · about 17 minutes

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STEP 1

Designer meets object

A constructor is called when an object is created. His name matches the class name. He can immediately get the name of the pet.

class Cat {
    String name;
    Cat(String newName) {
        name = newName;
    }
}

✦ Now the cat can be named immediately.

STEP 2

Pass the name to new.

When creating, specify the word in parentheses. The designer will save it in the object field.

Cat cat = new Cat("Рыжик");
System.out.println(cat.name);

✦ It'll make Red.

IN-CLASS PRACTICE

Type the code yourself

Type an example manually. Check the signs and brackets.

public class Main {
    public static void main(String[] args) {
        Cat cat = new Cat("Рыжик");
        System.out.println(cat.name);
    }
}
class Cat {
    String name;
    Cat(String newName) {
        name = newName;
    }
}

Open the editor for class work

HOMEWORK

Solve it yourself

Make a Dog class with a String name field and a Dog constructor (ZString newName), which retains the name. In main, create Dog with the name «Бим» and output dog.name.

The answer is hidden. Use similar examples from the lesson notes.

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