您可以访问数组内的javascript自定义类对象吗？如何访问？

Question

Im working on a RPG-game project made in plain javascript just for fun, but can't seem to understand how javascript build-in classes work since they behave quite a lot differently than I am used to in Java or C#. So here is the problem:

If I have made custom class something along the lines like this:

Class Player_animation{

        constructor(animationX,animationY,animation_state,xPos,yPos,destX,destY){
                 this.animationX = animationX;
                 . 
                 . (the basic setup for all the attributes as the first one);
                 .

           set animationX(value){
               this._animationX = value;
           }
           //all the setters as that one


        update(){

            if(this._animationX===480 && this._animation_state==='idle')
               this._animationX=0;


            else if(this._animationX===720 && this._animation_state !== 'attack'){
               this._animationX=0;            
            }

            else if(this._animationX===840){
              this._animationX=0;
              this._animationY = 0;
              this._animation_state = 'idle';
           }

           if(this._xPos!== this._destX || this._yPos!== this._destY){

            if(this._xPos<this._destX){
                this._animation_state = 'facing_right';
                this._animationY = 240;
            }
            if(this._xPos>this._destX){
                this._animation_state = 'facing_left';
                this._animationY = 360;
            }           
          }
          else{
            if(this._animation_state === 'facing_right')
                this._animationY = 0;
            if(this._animation_state === 'facing_left')
                this._animationY = 120;
            if(this._animation_state!=='attack'){
                this._animation_state = 'idle';
            }
        }        


  }

}

And i can call an new made class object no problem in my program like this:

var player_animation = new Player_animation(0,0,'idle',0,0,0,0);

player_animation.update();

Can I somehow make an array of these custom classes that I call with that function. I have tried two of the following approaches like this:

var array = [];
array.push[player_animation,player_animation2];
for(var unit in array){
   unit.update();
}

Second approach i tried that does not work:

var array = [];
array.push[player_animation,player_animation2];
for(var i = 0; i < array.Lenght; i++){
  array[i].update();
}

Working code goes through this loop (I know that I should limit the fps here):

function frame(){
    update();

    requestAnimationFrame(frame);
}

function update(){

    player_animation.update();
    enemy_animation.update();

}

requestAnimationFrame(frame);

Is something like this even possible in plain javascript? My game loop and update work fine with all of the objects defined called separately but that will be a hassle after there will be 10+ objects in game. In Java i was able to store all of the game_objects in an array where their functions would be called through a for loop so finding it hard to understand why it does not work as that in javascript.

Answer 1

You have many problems, none of them relating to how classes work in JavaScript.

 array.push[player_animation,player_animation2]; 

push is a function . You call it with () not [] .

 for(var unit in array){ 

in loops over the property names in an object . Avoid using it for arrays. If you do use it, then you would need array[unit] to get the value and not simply unit .

 for(var i = 0; i < array.Lenght; i++){ 

• JavaScript is case-sensitive
• JavaScript requires that property names be spelt correctly

It is length not Lenght .