I am working on a project for a beginner programming course. I am making a simple game where a vacuum character needs to collect small brown circles (rubbish) by moving over them and using a suction device, whilst avoiding moving spikey balls. My character moves using the mouse and uses his suction device when a key is pressed. I have an array of rubbish set up but I have been struggling to figure out how to remove a specific one when a key is pressed and the mouse/character collides with it. I would also like this to count up a score displayed on screen but this is not a priority. I have pasted my code below, sorry if it is really messy, I am not very good at this. TLDR: I want to remove a specific object from an Array when the player has a key pressed and their mouse is colliding with it. ArrayList rubbishArray = new ArrayList (); Spikeyball1 s1; Spikeyball1 s2; int x = 0; int y = 0; int p = 0; int borderY = 300; int gameScreen = 0; void setup() { size( 1600, 1000 ); s1 = new Spikeyball1(500, 300); s2 = new Spikeyball1(1100, 1000); for (int i = 0; i < 10; i++) { rubbishArray.add(new Rubbish()); } } void draw() { if (gameScreen == 0) { initScreen(); } else if (gameScreen == 1) { gameScreen(); } else if (gameScreen == 2) { gameOverScreen(); } } void initScreen() { background(0); textAlign(CENTER); textSize(50); text("Click to Start", 800, 500); } void gameScreen() { environment(); noCursor(); if (rubbishArray.size() < 10) { rubbishArray.add(new Rubbish()); } for (Rubbish r : rubbishArray) { r.move(); r.display(); } //top border if (mouseY<borderY) mouseY = borderY; //move vacuum if (keyPressed) p = 20; else p = 0; //spikeyballs s1.move(); s1.display(); s2.move(); s2.display(); s1.collision(); s2.collision(); //character vacuum(mouseX, mouseY+p); characterA(mouseX, mouseY); } void gameOverScreen() { background(210); textAlign(CENTER); textSize(50); text("Game Over!", 800, 400); text("Click to Restart", 800, 600); } void startGame() { gameScreen=1; } void mousePressed() { if (gameScreen==0) { startGame(); } if (gameScreen==2) { startGame(); } } void characterA(float x, float y) { stroke( 0 ); strokeWeight( 2 ); fill(0, 0, 102); ellipse(x-25, y+10, 15, 15); ellipse(x-8, y+10, 15, 15); ellipse(x+9, y+10, 15, 15); ellipse(x+26, y+10, 15, 15); fill(0, 76, 153); quad(x+5, y-73, x+8, y-103, x+18, y-100, x+15, y-70); quad(x-15, y-70, x-18, y-100, x-8, y-103, x-5, y-73); fill(0, 76, 153); rect(x-35, y-45, 70, 50); fill(0, 100, 153); arc(x, y-45, 70, 60, PI, TWO_PI); fill(255); ellipse(x-13, y-100, 15, 15); ellipse(x+13, y-100, 15, 15); fill(0); ellipse(x-13, y-100, 5, 5); ellipse(x+13, y-100, 5, 5); noFill(); arc(x, y-65, 20, 20, 0, PI); } void vacuum(float x, float y) { stroke( 0 ); strokeWeight( 2 ); fill(0, 100, 153); quad(x+25, y-30, x+35, y-20, x+65, y-50, x+55, y-60); fill(0, 76, 153); quad(x+45, y-50, x+75, y-20, x+85, y-30, x+55, y-60); fill(0, 100, 153); triangle(x+56, y-13, x+96, y-13, x+76, y-43); } void environment() { fill(150); quad(-500, 300, -200, 300, 100, 1000, -200, 1000); fill(125); quad(-200, 300, 100, 1000, 400, 1000, 100, 300); fill(150); quad(400, 1000, 100, 300, 400, 300, 700, 1000); fill(125); quad(400, 300, 700, 1000, 1000, 1000, 700, 300); fill(150); quad(700, 300, 1000, 1000, 1300, 1000, 1000, 300); fill(125); quad(1000, 300, 1300, 1000, 1600, 1000, 1300, 300); fill(150); quad(1300, 300, 1600, 1000, 1900, 1000, 1600, 300); fill(220); rect(-10, 0, 1650, 100); fill(200); rect(-10, 100, 1650, 100); fill(220); rect(-10, 200, 1650, 100); fill(10); rect(1000, 100, 300, 100); beginShape(); fill(240); vertex(300, 300); vertex(450, 300); vertex(450, 0); vertex(350, 0); vertex(300, 100); endShape(CLOSE); beginShape(); vertex(600, 300); vertex(450, 300); vertex(450, 0); vertex(550, 0); vertex(600, 100); endShape(CLOSE); } class Rubbish { float x; float y; float speed = random(2, 5); float r = random(80, 150); float g = random(45, 55); float b = 0; Rubbish() { x = 0; y = random(400, 900); } void move() { x+= speed; if (x>1600) { x=0; } } void display() { fill(r, g, b); ellipse(x, y, 30, 30); } } class Spikeyball1 { float xpos; float ypos; float r; boolean movingUp = true; int m = 0; boolean collision; Spikeyball1(float tempXpos, float tempYpos) { xpos = tempXpos; ypos = tempYpos; } void move() { if (movingUp) ypos += 3; else ypos -= 3; if (ypos 1000) movingUp = !movingUp; } void collision() { if ( mouseX >= xpos-50 && mouseX = ypos-50 && mouseY <= ypos+100) { gameScreen = 2; }; } void display() { stroke( 0 ); strokeWeight( 2 ); fill(60, 1, 1); beginShape(); vertex(xpos, ypos-50); vertex(xpos+14, ypos-20); vertex(xpos+47, ypos-15); vertex(xpos+23, ypos+7); vertex(xpos+29, ypos+40); vertex(xpos, ypos+25); vertex(xpos-29, ypos+40); vertex(xpos-23, ypos+7); vertex(xpos-47, ypos-15); vertex(xpos-14, ypos-20); endShape(CLOSE); fill(200, 20, 10); ellipse(xpos, ypos, 50, 50); fill(255); ellipse(xpos+8, ypos-5, 10, 10); ellipse(xpos-8, ypos-5, 10, 10); fill(0); ellipse(xpos+8, ypos-5, 3, 3); ellipse(xpos-8, ypos-5, 3, 3); noFill(); arc(xpos, ypos+15, 25, 20, PI, TWO_PI); } }

[image] Ohli: how do I tell it that (i) is the object colliding with the mouse. That’s right! My answer was a bit too short. For example you for loop over all rubbish: When the Distance to the mouse is = 0; i--) { Rubbish item=list.get(i); ` if (item.isDead) list.remove(i); } Chrisir

list.remove(i) When you need to remove multiple items, use a for loop which must go backward

I am not sure how to apply this. I know that I can remove specific objects from an array, but how do I tell it that (i) is the object colliding with the mouse. Also I don’t think I can use list.remove(i) in Java, please correct me if I am wrong.

[image] Ohli: Also I don’t think I can use list.remove(i) in Java, please correct me if I am wrong. ArrayList / Reference / Processing.org :)

[image] Chrisir: , use a for loop which must go backward. [image] Table removeColumn(index) not working correctly? Coding Questions For completeness’ sake, although I prefer backwards back loops for deleting elements, here’s how to do the same w/ a forward arrow_forward loop the right way: smile_cat final IntList nums = IntList.fromRange(10); println(nums); println("Forwards:"); for(int i = 0; i < nums.size(); ++i) { println("index:", i, TAB, "value:", nums.get(i)); nums.remove(i--); } println(nums); exit(); B/c we’re emptying the whole container, the index i is stuck at value 0 on all iterations. open_mouth …

Thank you so much! I got it working :smiley: I had one more question though, how would I go about making it so that each item removed adds to a score that I display on screen?

Nevermind I managed to implement a score all by myself xD Thanks again This was giving me a headache for ages!

I am glad to hear this! Congratulations! Chrisir

How to remove a specific object from an Arraylist

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GoToLoop October 14, 2020, 5:29pm 5

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How to remove a specific object from an Arraylist

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