for(let i=0;i<selectedGroup.children.length;i++){
let group = selectedGroup.children[i];
delete shapeList[group.myShapeIndex];//删除指定下标元素，不改变shapeList长度
}
shapeList = shapeList.filter(Boolean);//清除数组中的空元素
标签：删除,元素,指定,标的,循环,数组 From： https://www.cnblogs.com/shark1100913/p/17151081.html