destroy() specific item from group?

[hustlerinc]

Hi, I just started playing around with Phaser and I need some help. I have a group named coins, and I want to delete each coin inside if it's x position is less than 0.

 

I add the coins like this:

for (i = 0; i < coinArray.length; i++) {    var coin = coins.create(game.world.width + coinArray[i].x, coinArray[i].y, 'coin');    coin.body.velocity.x -= 250;}

How can I do this?

[Dumtard]

group.forEach(function(coin) {

if (coin.x < 0) {

coin.destroy();

}

}, this);

[hustlerinc]

group.forEach(function(coin) {  if (coin.x < 0) {    coin.destroy();  }}, this);

I tried your code (changed group to coins) but the script dies when the first coin reaches the border and I get "Cannot read property 'x' of undefined". I updated my first post to show how the coins are added.

[Heppell08]

function coinKill(coin)

{ if(coin.x < 0) {coin.destroy();} }

Its how I kill coins but its similar to collide coding the coins. You shouldn't need to reference the actual group itself because you can reference the children (coin) instead.

[hustlerinc]

function coinKill(coin)

{ if(coin.x < 0) {coin.destroy();} }

Its how I kill coins but its similar to collide coding the coins. You shouldn't need to reference the actual group itself because you can reference the children (coin) instead.

For some reason as soon as I try to look at a property of "coin" I get the same error. It works fine for collision between player and coin where I do this:

function collectCoin (player, coin) {    coin.destroy();}game.physics.arcade.overlap(player, coins, collectCoin, null, this);

but when I try your code I get the same undefined error. What am I missing?

[Heppell08]

Place coin as global and not anon in your create function.

[hustlerinc]

Place coin as global and not anon in your create function.

You mean something like just "var coin;" right? Doesn't work. And if that was the problem my collectCoin() function wouldn't work either. Also I have to create the coins in update() as it's random. The create function is just called once right?

[Heppell08]

Hmm, well if even making it global doesn't help them maybe trying to user a getAt() in a loop and cycling them. I would have thought a forEach would do the job or a getFirstDead() cycling the group would do the work for you.

[Heppell08]

Maybe set them to out of bounds kill so when they go off screen they are killed that way?

[hustlerinc]

Maybe set them to out of bounds kill so when they go off screen they are killed that way?

How would I do that? I just started learning Phaser today.

[Dumtard]

Try this instead of my original post.

for (var i = 0; i < coins.children.length;) {  if (coins.children[i].x < -coins.children[i].width) {    coins.remove(coins.children[i], true);    continue;  }  i++;}

jsfiddle of it working.

 

Basically what happened with my first post is classic example of removing from a list while iterating over it. It screws with the indexing. I originally meant coins.remove(coin, true) figuring the group would handle the removed coins but it also was getting undefined coins. So just went with a more classic approach to the problem, handling the loop indexing myself instead of blindly incrementing like forEach seems to.


EDIT:

Here is a jsfiddle closer to what I originally meant to do handling the undefined coins.

[hustlerinc]

Try this instead of my original post.

for (var i = 0; i < coins.children.length;) {  if (coins.children[i].x < -coins.children[i].width) {    coins.remove(coins.children[i], true);    continue;  }  i++;}

jsfiddle of it working.

 

Basically what happened with my first post is classic example of removing from a list while iterating over it. It screws with the indexing. I originally meant coins.remove(coin, true) figuring the group would handle the removed coins but it also was getting undefined coins. So just went with a more classic approach to the problem, handling the loop indexing myself instead of blindly incrementing like forEach seems to.

Perfect, this does the trick. Thank you.

[amuseum]

yea , be careful when you try to delete objects in a foreach loop. sometimes i even work backwards through the indexes. to check and delete the last object in the list first.

[SatriaAI]

On 8/9/2014 at 5:30 AM, Dumtard said:

Try this instead of my original post.

for (var i = 0; i < coins.children.length;) {  if (coins.children[i].x < -coins.children[i].width) {    coins.remove(coins.children[i], true);    continue;  }  i++;}

jsfiddle of it working.

 

Basically what happened with my first post is classic example of removing from a list while iterating over it. It screws with the indexing. I originally meant coins.remove(coin, true) figuring the group would handle the removed coins but it also was getting undefined coins. So just went with a more classic approach to the problem, handling the loop indexing myself instead of blindly incrementing like forEach seems to.


EDIT:

Here is a jsfiddle closer to what I originally meant to do handling the undefined coins.

Does this trick ca be paired with time.events.loop?

Like this?

Quote

this.meLoop = this.game.time.events.loop(this.rndTime, spawn, this);