两种方法把类和对象写在同一个文件内

package ch07;

/**两种方法把类和对象写在同一个文件内
 * Created by liwenj on 2017/7/20.
 */
//1
public class Cell {
    String pp;

    void cd() {
        System.out.println("品牌是" + pp + "可以充电");
    }

    public static void main(String[] args) {
        Cell PP = new Cell();
        PP.pp = "华为";
        PP.cd();

    }
}

//2
public class Cell {
    String pp;

    void cd() {
        System.out.println("品牌是" + pp + "可以充电");
    }

}

class TestCell {
    public static void main(String[] args) {
        Cell PP = new Cell();
        PP.pp = "华为";
        PP.cd();

    }
}