Just invoke the removeObject method of the World class and pass in the object to be re-moved as a parameter (in some sense removeObject is the opposite of the addObject method). addObject (mark, 0,markRoverY) addObject (rover, 0,markRoverY) if you want the combined height of the two objects you will have to store a variable of both heights added and then.
#REMOVE OBJECT GREENFOOT HOW TO#
So I'm open to any examples or ideas as to what I'm doing wrong or simply not understanding about this "getWorld().Introduction 1 Chapter 1 Getting to know Greenfoot 3 1.1 Getting started 3 1.2 Objects and classes 4 1.3 Interacting with objects 6 1.4 Return types 7 1.5 Parameters 8 1.6 Greenfoot execution 9 1.7 A second example 10 1.8 Understanding the class diagram 10 1.9 Playing with Asteroids 12 1.10 Source code 13 1.11 Summary 15 Chapter 2 The first program: Little Crab 16 2.1 The Little Crab scenario 16 2.2 Making the crab move 18 2.3 Turning 19 2.4 Dealing with screen edges 21 2.5 Summary of programming techniques 25 Chapter 3 Improving the Crab-more sophisticated programming 27 3.1 Adding random behavior 27 3.2 Adding worms 30 3.3 Eating worms 32 3.4 Creating new methods 33 3.5 Adding a Lobster 36 3.6 Keyboard control 36 3.7 Ending the game 38 3.8 Adding sound 40 3.9 Summary of programming techniques 42 Chapter 4 Finishing the crab game 43 4.1 Adding objects automatically 43 4.2 Creating new objects 45 4.3 Animating images 46 4.4 Greenfoot images 47 4.5 Instance variables (fields) 48 4.6 Assignment 49 4.7 Using actor constructors 50 4.8 Alternating the images 52 4.9 The if/else statement 53 4.10 Counting worms 53 4.11 More ideas 55 4.12 Summary of programming techniques 56 Interlude 1 Sharing your scenarios 57 I1.1 Exporting your scenario 57 I1.2 Export to application 57 I1.3 Export to a web page 58 I1.4 Publishing on the Greenfoot Gallery 59 Chapter 5 Making music: An on-screen piano 61 5.1 Animating the key 62 5.2 Producing the sound 65 5.3 Abstraction: Creating multiple keys 66 5.4 Building the piano 68 5.5 Using loops: The while loop 69 5.6 Using arrays 72 5.7 Summary of programming techniques 76 Chapter 6 Interacting objects: Newton''s Lab 78 6.1 The starting point: Newton''s Lab 79 6.2 Helper classes: SmoothMover and Vector 80 6.3 The existing Body class 83 6.4 First extension: Creating movement 85 6.5 Using Java library classes 86 6.6 Adding gravitational force 87 6.7 The List type 90 6.8 The for-each loop 91 6.9 Applying gravity 93 6.10 Trying it out 95 6.11 Gravity and music 97 6.12 Summary of programming techniques 99 Chapter 7 Collision detection: Asteroids 101 7.1 Investigation: What is there? 102 7.2 Painting stars 103 7.3 Turning 106 7.4 Flying forward 107 7.5 Colliding with asteroids 109 7.6 Casting 112 7.7 Adding fire power: The proton wave 115 7.8 Growing the wave 115 7.9 Interacting with objects in range 119 7.10 Further development 121 7.11 Summary of programming techniques 122 Interlude 2 The Greeps competition 123 I2.1 How to get started 124 I2.2 Programming your Greeps 125 I2.3 Running the competition 126 I2.4 Technicalities 126 Chapter 8 Creating images and sound 127 8.1 Preparation 127 8.2 Working with sound 129 8.3 Sound recording and editing 130 8.4 Sound file formats and file sizes 131 8.5 Working with images 133 8.6 Image files and file formats 133 8.7 Drawing images 135 8.8 Combining images files and dynamic drawing 137 8.9 Summary 139 Chapter 9 Simulations 141 9.1 Foxes and rabbits 142 9.2 Ants 145 9.3 Collecting food 146 9.4 Setting up the world 149 9.5 Adding pheromones 149 9.6 Path forming 152 9.7 Summary 152 Chapter 10 Additional scenario ideas 154 10.1 Marbles 154 10.2 Lifts 155 10.3 Boids 156 10.4 Circles 157 10.5 Explosion 158 10.6 Breakout 159 10.7 Platform jumper 160 10.8 Wave 161 10. Section 3: Removing Objects It is fairly easy to remove an object from a Greenfoot World. First get the numbers you need and store them as variables: int markRoverY (int) (Math.random ()getHeight ()) and then add the objects with the same variable. (e.g a button is created on the screen, you click on that button and only that button is removed, not the other two buttons that were loaded)
![remove object greenfoot remove object greenfoot](https://i.ytimg.com/vi/gicCTNxLGEM/maxresdefault.jpg)
And I keep getting a compile error.Īlso I'm trying to do this from within a subclass actor when it's clicked on. I've tried many variations of this as well, and all bring about the wrong result. I've tried using: "getWorld().removeObjects(Startup) " where 'startup' is the name of the object/class I'm trying to remove from the world. Loads the Color choice buttons (White or Black)Īnd this works fine, but the issue I'm now having is after the user selects one of the objects on the screen, it doesn't remove all the objects I'm wanting. : A screenshot of the Greenfoot environment showing how to remove an.
![remove object greenfoot remove object greenfoot](https://mrdoran.files.wordpress.com/2016/06/counter.png)
I've been through this forum, and I've yet to find a piece of code to simply do what I'm wanting.įirst off, I've added some items to the world with : To remove an object from a World, right-click on the object and select Remove/Delete.