Greenfoot

Heet_Patel

2018/2/9

#

Hi but could i have the code for placing objects into the world. There should be at least five of them spawning. My World class is The_House and my actors are Villian and The_Jail. It would be better if I could have seven of The_Jail.

danpost

2018/2/9

#

You can get random coordinates:

1 2	`int` `x = Greenfoot.getRandomNumber(getWidth());` `int` `y = Greenfoot.getRandomNumber(getHeight());`

for each actor you wish to add. You can even create a method to place a given actor anywhere randomly in the world:

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public void addActor(Actor actor)
{
    int x = Greenfoot.getRandomNumber(getWidth());
    int y = Greenfoot.getRandomNumber(getHeight());
    addObject(actor, x, y);
}

then, for example, add an actor like so:

1	`addActor(new` `Villian());`

or multiple actors like so:

1	`for` `(int` `i=0; i<7; i++) addActor(new` `The_Jail());`

Heet_Patel

2018/2/11

#

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public void addActor(Actor actor)
 
{
int x = Greenfoot.getRandomNumber(getWidth());
int y = Greenfoot,getRandomNumber(getHeight());
addObject(Villian,x,y)
}

Is this the correct code if i want the villian toget added. Does this code also add random number or just random places.

Super_Hippo

2018/2/11

#

He gave you the correct codes, you don't need to change them.

danpost

2018/2/11

#

For random number (and random locations):

1	`for` `(int` `i=0; i<1+Greenfoot.getRandomNumber(7); i++) addActor(new` `The_Jail());`

This places a minimum of one and a maximum of 7 The_Jail actors into the world at random places.

Super_Hippo

2018/2/11

#

For same chances to get any number of The_Jail actors (1..7), you can use:

1	`for` `(int` `i=1+Greenfoot.getRandomNumber(7); i>0; i--) addActor(new` `The_Jail());`

(At least, as far as I know, the condition will be executed again all the time, so the chance to get 7 Jail_Actors in the world with danpost's code is only 0.612 %.)

danpost

2018/2/11

#

@Hippo, you are correct (I did not think about the repeated execution of the limit check which would change the limit each time). I should have got an absolute limit first:

1 2	`int` `count =` `1+Greenfoot.getRandomNumber(7);` `for` `(int` `i=0; i<count; i++) addActor(new` `The_Jail());`

which would also give equal chance.

Heet_Patel

2018/2/14

#

danpost wrote...

You can get random coordinates:

1 2	`int` `x = Greenfoot.getRandomNumber(getWidth());` `int` `y = Greenfoot.getRandomNumber(getHeight());`

for each actor you wish to add. You can even create a method to place a given actor anywhere randomly in the world:

1

2

3

4

5

6

public void addActor(Actor actor)
{
    int x = Greenfoot.getRandomNumber(getWidth());
    int y = Greenfoot.getRandomNumber(getHeight());
    addObject(actor, x, y);
}

then, for example, add an actor like so:

1	`addActor(new` `Villian());`

or multiple actors like so:

1	`for` `(int` `i=0; i<7; i++) addActor(new` `The_Jail());`

it says that after the first bracket for the (getHeight()); i need a semi colon(;)

Heet_Patel

2018/2/14

#

then it says that it cannot find symbol for getWidht and getHeight it also says that t cannotfind the method for addObject

Super_Hippo

2018/2/14

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You need to place the method into your world subclass, not an actor subclass. Or you need to add a 'getWorld().' before all used world methods.

Heet_Patel

2018/2/16

#

ok tnx guys

Heet_Patel

2018/2/16

#

i got it to work kind o like the way i wanted it to.

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