跳出双层for循环

  switch (a)
    {
        case 1:
        {
            
        }break;
            
        case 4:
        {
            for (int i=0;i<2;i++)
            {
                for (int j=0;j<2;j++)
                {
                    UILabel *la=[[UILabel alloc]init];
                    la.backgroundColor=[UIColor blackColor];
                    la.frame=CGRectMake(100+j*35,100+i*35,30,30);
                    [self.window addSubview:la];
                }
            }
        }break;
        case 2:
        case 3:
        case 5:
        case 6:
        case 7:
        case 8:
        case 9:
        {
            int x;
            for (int i=0;i<3;i++)
            {
                if (i==x)
                {
                    break;
                }
                for (int j=0;j<3;j++)
                {
                    if (i*3+j==a)
                    {
                        x=i+1;
                        break;
                    }
                    UILabel *la=[[UILabel alloc]init];
                    la.backgroundColor=[UIColor blackColor];
                    la.frame=CGRectMake(100+j*35,100+i*35,30,30);
                    [self.window addSubview:la];
                }
            }
        }break;
        default:
            break;
    }