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Added balls, random color, random number. #1998

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Added balls, random color, random number. #1998

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d8729ad
Added balls, random color, random number.
Papugo-FS Jan 28, 2026
58dc597
small fix
Papugo-FS Jan 28, 2026
871e5e6
small fix
Papugo-FS Jan 28, 2026
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4 changes: 3 additions & 1 deletion src/main/java/core/basesyntax/Application.java
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Original file line number Diff line number Diff line change
Expand Up @@ -2,6 +2,8 @@

public class Application {
public static void main(String[] args) {
// create three balls using class Lottery and print information about them in console
for (int i = 0; i < 3; i++) {
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@mateacademy-ai-mentor mateacademy-ai-mentor Jan 28, 2026

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This violates checklist item #9: 'All magic numbers in your code should be constants.' The number 3 should be declared as a named constant to improve readability and make the code easier to maintain.

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@mateacademy-ai-mentor mateacademy-ai-mentor Jan 28, 2026

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This violates checklist item #9: 'All magic numbers in your code should be constants.' The number 3 should be extracted into a private static final constant to improve readability and maintainability.

System.out.println(new Lottery().getRandomBall());
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@mateacademy-ai-mentor mateacademy-ai-mentor Jan 28, 2026

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This violates checklist item #4: 'Don't create several instances of the same class if you can use only one instance for your purposes'. The Lottery object should be created once, before the loop. Then, you can call its getRandomBall() method multiple times on the same instance inside the loop.

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@mateacademy-ai-mentor mateacademy-ai-mentor Jan 28, 2026

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This violates checklist item #4: 'Don't create several instances of the same class if you can use only one instance for your purposes'. You should create the Lottery instance once, before the for loop begins, and then call the getRandomBall() method on that same instance within the loop.

}
}
}
30 changes: 30 additions & 0 deletions src/main/java/core/basesyntax/Ball.java
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@@ -0,0 +1,30 @@
package core.basesyntax;

public class Ball {
private String color;
private int number;

public String getColor() {
return this.color;
}

public void setColor(String color) {
this.color = color;
}

public int getNumber() {
return this.number;
}

public void setNumber(int number) {
this.number = number;
}

@Override
public String toString() {
return "Ball{ "
+ "color='" + getColor() + '\''
+ "number='" + getNumber() + '\''
+ '}';
}
}
6 changes: 5 additions & 1 deletion src/main/java/core/basesyntax/ColorSupplier.java
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@@ -1,7 +1,11 @@
package core.basesyntax;

import java.util.Random;

public class ColorSupplier {
private final Random random = new Random();

public String getRandomColor() {
return null;
return Colors.values()[random.nextInt(Colors.values().length)].toString();
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@mateacademy-ai-mentor mateacademy-ai-mentor Jan 28, 2026

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This violates checklist item #10: "Use name() for getting String representation of enum constants". The name() method is preferred for enums as it guarantees returning the constant's name, whereas toString() can be overridden.

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@mateacademy-ai-mentor mateacademy-ai-mentor Jan 28, 2026

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This violates checklist item #10: 'Use name() for getting String representation of enum constants'. As mentioned in the previous review, it's better to use the name() method for enums, as toString() can be overridden and might not return the constant's name.

}
}
10 changes: 10 additions & 0 deletions src/main/java/core/basesyntax/Colors.java
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@@ -0,0 +1,10 @@
package core.basesyntax;

public enum Colors {
BLACK,
BLUE,
RED,
WHITE,
PURPLE,
PINK
}
16 changes: 16 additions & 0 deletions src/main/java/core/basesyntax/Lottery.java
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@@ -0,0 +1,16 @@
package core.basesyntax;

import java.util.Random;

public class Lottery {
private static final int FIGURE_COUNT = 101;
private final Random random = new Random();

public Ball getRandomBall() {
Ball ball = new Ball();
String randomColor = new ColorSupplier().getRandomColor();
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@mateacademy-ai-mentor mateacademy-ai-mentor Jan 28, 2026

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This line has two issues:

  1. It violates checklist item Wrote an assignment jv-lottery. #4: 'Don't create several instances of the same class if you can use only one instance for your purposes'. A new ColorSupplier instance is created every time this method is called. It would be more efficient to create a single ColorSupplier instance as a private field in the Lottery class and reuse it.

  2. It violates checklist item Create random colorand number of ball #2: 'Don't create temporary variables if you can directly return value from the method'. The randomColor variable is unnecessary. You can set the color directly on the ball object.

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This violates checklist item #5: 'Dependencies like services should be class-level fields rather than local variables in a method'. The ColorSupplier should be instantiated once as a private field in the Lottery class and reused, just as you've done with the Random object.

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This violates checklist item #5: 'Think about which variables should be local in the method and which should be class-level'. The ColorSupplier is a dependency of the Lottery class. It should be created once as a private final field of the Lottery class, rather than creating a new instance every time getRandomBall() is called.

ball.setColor(randomColor);
ball.setNumber(random.nextInt(FIGURE_COUNT));
return ball;
}
}