How to store objects from a class in an array

Question

Hi so I have been tasked with creating a "falling game" and I have classes for each thing such as the user and the enemy. I was wondering how would I go about storing the enemies in an array. I have done some research and trial and testing and it seems like I need to use an array of objects to store these in an array and call them from the array. Am I right in believing so? I tried storing them in an array for PImage but that did not work I am not sure how to create an array of objects. Here is my class for the enemy which is called salad lol:

class Salad {
 float x,y;
 float speedX, speedY; //declaring variables
 PImage saladImage;

 Salad(int x, int y, int speedY) {
  this.x = x;
  this.y = y;
  this.speedY = speedY;
  saladImage = loadImage("salad.png");
  saladImage.resize (60, 52);  
 } //end of salad

 void move() {
   y=y-speedY;
   float stepY = random(-5,5);
   y = y + (int)stepY;

   float rand = random(25,475);
   int intRand = int(rand);   

   if (this.y < 0) {
    this.y = 900; // once the salads y is less than 0 they restart at 900
    this.x = intRand;
    speedY = speedY + 0.5;
   }
 } //end of void move

 //draw a salad
 void render()
 {
image(saladImage,x,y);

} //end of void render 

 void update() {
  move();
  render();
 }
}// end of alien class

Here is my main class and i wanted to store the burger and salad class in the array if that was possible:

PImage background;
PImage MenuBackground;
int y=0;//global variable background location
final int End = 0;
final int Active = 1;
final int Menu = 2;
int gameMode = Menu;
int score = 0;
int lives = 3;
Boolean BurgerCollisionInProgress = false;
Boolean BurgerCollisionInProgress2 = false;


Salad salad1;
Salad salad2;
Salad salad3;
Homer user1;
Burger Burger;


public void settings() {
 size(500,1000); //setup size of canvas
}

void menu() {
 background = loadImage("spaceBackground.jpg"); //image used for background
 background.resize(500,1000); //resizes the background
 gameMode = Active; 

float rand = random(25,475);
int intRand = int(rand);

float rand2 = random(25,475);
int intRand2 = int(rand2); 

float rand3 = random(25,475);
int intRand3 = int(rand3); 

float rand4 = random(25,475);
int intRand4 = int(rand4); 


 user1 = new Homer(250,100);  //declares new defender as user1
 Burger = new Burger(intRand,900,2);
 salad1 = new Salad(intRand2,900,3);
 salad2 = new Salad(intRand3,900,3);
 salad3 = new Salad(intRand4,900,3); //3 aliens declared with their x and y position and their speed they move at
 draw();
}


void setup() {
  if(gameMode == 2) {    
    MenuBackground = loadImage("simpMenu.png");
    MenuBackground.resize(540,1000);
    image(MenuBackground, 0, y);
    textAlign(CENTER);
    textSize(40);
    fill(252, 3, 3);
    text("Press 'p' to play", 250,500);     
  } 
}


void draw () {  
  if (gameMode == Active) {        
    if(crash() == false) {
      drawBackground();//calls the drawBackground method
      textSize(32);
      fill(22,100,8);
      text("Score: " + score,75,40); 
      text("Lives: " + lives,75,80);
      salad1.update();//calls the update method which holds the move and render methods for alien
      salad2.update();
      salad3.update();
      user1.render();//calls the update method which holds the move and render methods for user
      Burger.update();//calls the update method which holds the move and render methods for burger

      if(Bcrash() == true && BurgerCollisionInProgress == false) {
      score = score+1;
      BurgerCollisionInProgress = true;
      Burger.y = 900;
      float rand = random(25,475);
      int intRand = int(rand);
      Burger.x = intRand;
      }

      if(Bcrash() == false) {
      BurgerCollisionInProgress = false;
      }


      if(crash() == true && BurgerCollisionInProgress2 == false) {
        if (lives < 1) {   gameMode = End;
            textSize(28);
            fill(22,100,8);
            text("Game Over, press 'r' to restart",50,200);
        }
        else {
          lives = lives - 1;
          BurgerCollisionInProgress2 = true;
          menu();
          //salad1.update();
          //salad2.update();
          //salad3.update();
        }
        if (crash() == false) {
          BurgerCollisionInProgress2 = false;
      }
     }      
    }
  }
}

void drawBackground() {
 image(background, 0, y); //draw background twice adjacent
 image(background, 0, y-background.width);
 y -=2;
 if(y == -background.width)
 y=0; //wrap background
}


void keyPressed() //allows the user to press the up and down keys to move the defender
{ 
  if(key == CODED) {
     if (keyCode == UP) {
       user1.y = user1.y - 7;
     }

     else if (keyCode == DOWN) {
       user1.y = user1.y + 7;
     }

     else if (keyCode == LEFT) {
       user1.x = user1.x - 7;
     }

     else if (keyCode == RIGHT) {
       user1.x = user1.x + 7;
     }

  } //key   

  if(key=='r') {
       menu();
     }

     if(key=='p') {
       menu();
     }
}


  boolean crash() {
    if(user1.crash(salad1)) {
      return true;
    }
    if(user1.crash(salad2)) {
      return true;
    }
    if(user1.crash(salad3)) {     
      return true;
    }
    return false;
  }


  boolean Bcrash() {
    if(user1.crash(Burger))
    {      
      return true;
    }
    return false;
  }

0xh3xa · Accepted Answer · 2020-03-23 17:10:32Z

1

You can create an interface called Food and implement in Salad and Burger and Create a list of Food

public interface Food {}
public class Salad implements Food {}
public class Salad implements Burger {}

and Create a list by:

List<Food> list = new ArrayList<>();
Burger burger = new Burger();
Salad salad = new Salad();

list.add(burger);
list.add(salad);

, And you can check them when retrieving by

Food food = list.get(0);
if (food instanceof Salad) {
  Salad s = (Salad) food;
  // do somesthing
} else if (food instanceof Burger) {
  Burger b = (Burger) food;
  // do somesthing
}

answered Mar 23, 2020 at 17:10

0xh3xa

4,8672 gold badges17 silver badges30 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

laancelot · Accepted Answer · 2020-03-23 16:56:49Z

0

Here's the syntax: Let's say you want an ArrayList of Salad:

ArrayList<Salad> mySalads = new ArrayList<Salad>();

If you have only one image for your salads you may want to load it into a global variable just once and use it from there instead of loading it into memory for each instance of Salad, but that's another thing.

Your project looks interesting, have fun!

answered Mar 23, 2020 at 16:56

laancelot

3,1892 gold badges17 silver badges25 bronze badges

Collectives™ on Stack Overflow

How to store objects from a class in an array

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related