Don't know

Question about the task

Initializing cats

Java Syntax, Level 5, Lesson 7

Resolved

Why my program program does not compile?

Create a Cat class with five initializers:
- Name,
- Name, weight, age
- Name, age (standard weight)
- Weight, color (unknown name, address and age, i.e. a homeless cat)
- Weight, color, address (someone else's pet)

The initializer's job is to make the object valid.
For example, if the weight is unknown, then you need to specify some average weight.
A cat can't weigh nothing.
The same applies to age and color.
But there may or may not be a name (i.e. name might be null).
The same applies to the address (it might be null).

Requirements:

The program must not read data from the keyboard.
The Cat class must have a String variable name.
The Cat class must have an int variable age.
The Cat class must have an int variable weight.
The Cat class must have a String variable address.
The Cat class must have a String variable color.
The class must have an initialize method that takes a name as an argument, but initializes all variables except the address.
The class must have an initialize method that takes a name, weight, and age as arguments, but initializes all variables except the address.
The class must have an initialize method that takes a name and age as arguments, and initializes all variables except the address.
The class must have an initialize method that takes a weight and color as arguments, and initializes all variables except the name and address.
The class must have an initialize method that takes a weight, color, and address as arguments, but initializes all variables except the name.

package com.codegym.task.task05.task0510; /* Initializing cats */ public class Cat { private String name; private int age; private int weight; private String color; private String address ; public void initialize (String name) { this.name = name; this.age = age; this.weight = weight; this.color = color; } public void initialize (String name, int age, int weight) { this.name = name; this.age = age; this.weight = weight; this.color = color; } public void initialize (String name, int age) { this.name = name; this.age = age; this.weight = weight; this.color = color; } public void initialize (String color, int weight) { this.age = age; this.weight = weight; this.color = color; } public void initialize (int weight, String color, String address) { this.age = age; this.weight = weight; this.color = color; this.address = address; } public static void main(String[] args) { } }

Comments (2)

Popular
New
Old

You must be signed in to leave a comment

Nouser

Level 36 , Germany

28 August 2020, 11:23

solution

the methods public void initialize (String name, int age) public void initialize (String color, int weight) have the same signature initialize (String, int). The parameter names are not from intererst for the compiler. The next problem (not an error) is that

public void initialize (String name, int age)
{
    this.name = name;
    this.age = age;
    this.weight = weight;
    this.color = color;
}

name and age are OK, this.name refers to the field and name to the argument given in the method call. If you do the same with this.weight = weight; then there's no weight argument and therefore both, this.weight and weight refer to the field. So it's the same as writing this.weight = this.weight; or weight = weight; In the end weight is 0 cause that's the default for int fields. It's not wrong but may lead to mistakes.

Maxim Raitin

Level 20 , Tomsk, Russian Federation

28 August 2020, 13:06

thank you