arraysprocessingkhan-academy

When trying to remove an item from array errors

So when writing a game on Khan Academy When I try to remove a bullet from the array I run into the error "Object does not support method splice" I have been checking my code for hours and have not found out why it does not work. Ideas?

EDIT: The code used to remove a bullet is bullets[i].splice(i,1); and that is what errors out my code.

MVCE:

var bullets = [];

var bullet= function(x,y,blah)
{
    //code that is not important here
};

bullets.push(bullet(0,0,30));
for(var I = 0; I < bullets.length; I++){
if(bulletRemove){
bullets[I].splice(i,1)
}
}
Solution

  • You have a variable named bullets:

    var bullets = [];

    (Side note: Why is there a random curly bracket right before this line?)

    This bullets variable is an array. It holds instances of the Bullet class:

    bullets.push(new Bullet(x, y, 10, player.x+bSize/2, player.y+bSize/2));

    You can use the array to access a Bullet at a particular index, and then you can call functions of the Bullet class on that instance:

    bullets[i].move();

    You can also call the splice() function on the array itself:

    bullets.splice(i,1);

    However, you can't call the splice() function on a particular Bullet instance!

    bullets[i].splice(i,1);

    This line is taking an instance of Bullet from the i index of the bullets array, and then trying to call the splice() function from the Bullet class. But the Bullet class doesn't have a splice() function! This is what's causing the error.

    Instead, you probably meant to call it on the array itself:

    bullets.splice(i,1);

    In the future, please please please try to narrow your problem down before posting a question. Try to post an MCVE instead of your entire project. You could have put together an example program that used just a few lines to create a hard-coded array and used that to demonstrate your problem. Chances are you would have found the problem yourself in the process of creating the MCVE!