forEach => for

packages/artplayer/src/layer.js

@@ -3,10 +3,19 @@ import Component from './utils/component';
 export default class Layer extends Component {
     constructor(art) {
         super(art);
+
+        const {
+            option,
+            template: { $layer },
+        } = art;
+
         this.name = 'layer';
-        this.$parent = art.template.$layer;
+        this.$parent = $layer;
+
         art.once('ready', () => {
-            art.option.layers.forEach((item) => this.add(item));
+            for (let index = 0; index < option.layers.length; index++) {
+                this.add(option.layers[index]);
+            }
         });
     }
 }