• 2022-05-29
    下列哪个选项是创建一个标识有“关闭”按钮的语句?   ( )
    A: JTextField b = new JTextField("关闭");  
    B: JTextArea b = new JTextArea ("关闭");
    C: JButton b = new JButton("关闭");  
    D: JCheckbox b = new JCheckbox("关闭");
  • C

    内容

    • 0

      以下选项中,不可以通过( )操作退出PowerPoint。 A: 文件菜单下的"退出" B: 文件菜单下的"关闭" C: Alt+F4快捷键 D: 点击标题栏右端的"关闭"按钮

    • 1

      创建一个有“开始”按钮语句的是() A: JTextField b=new JTextField(“开始”); B: JButton b = new JButton(“开始”); C: JLabel b=new JLabel(“开始”); D: JCheckbox b=new JCheckbox(“开始”);

    • 2

      新建一个流对象,下列( )选项的代码是错误的。 A: new BufferedWriter(new FileWriter("a.txt")); B: new BufferedReader(new FileInputStream("a.dat")); C: new DataOutputStream(new FileOutputStream("a.txt")); D: new ObjectInputStream(new FileInputStream("a.dat"));

    • 3

      定义并初始化一个用于存放我们国家的四个直辖市的数组cityName,四个直辖市为:北京,上海,天津,重庆. 正确的是_________ A: String[] cityName=new String[4]{"北京","上海","天津","重庆"}; B: String[] cityName=new String[]{"北京","上海","天津","重庆"}; C: String[] cityName={"北京","上海","天津","重庆"}; D: String cityName = new String[4] { "北京", "上海", "天津", "重庆" };

    • 4

      下列定义字符串数组的语法正确的是( )? A: String[] list = new String[]{"red", "yellow", "green"}; B: String list = new String{"red", "yellow", "green"}; C: String list = {"red", "yellow", "green"}; D: String[] list = {"red", "yellow", "green"};