java小记（二）

快来打我* 2023-11-26 00:47 77阅读 0赞

1.String类的构造方法

转载博客:[https://blog.csdn.net/baidu\_33604078/article/details/78954704][https_blog.csdn.net_baidu_33604078_article_details_78954704]

2.输入String型数据

Scanner input = new Scanner(System.in);
    String str = input.next();//会从控制台读入一个字符串，以空格为标志
    String str = input.nextLine();//会从控制台读入一行字符串，以回车为标志
    //需要import java.util.Scanner;

3.在Eclipse中开启断言

转载链接:[https://jingyan.baidu.com/article/6f2f55a156b2d0b5b93e6cc2.html][https_jingyan.baidu.com_article_6f2f55a156b2d0b5b93e6cc2.html]  
[https://www.cnblogs.com/tjlgdx/p/6163517.html][https_www.cnblogs.com_tjlgdx_p_6163517.html]

4.`toCharArray()` 方法是将字符串转换为字符数组。

原型:`public char[] toCharArray()`

5.`calendar.get(....)`类

转载博客:[https://blog.csdn.net/weixin\_38610651/article/details/82796317][https_blog.csdn.net_weixin_38610651_article_details_82796317]

6.Math类

转载博客:[https://blog.csdn.net/js940814/article/details/80186857][https_blog.csdn.net_js940814_article_details_80186857]

7.`SimpleDateFormat`常用构造方法()

//1.
    DecimalFormat format = new DecimalFormat("###,####.000"); 
    
    System.out.println(format.format(111111123456.1227222)); 
    
    
    //2.
    Locale.setDefault(Locale.US); 
    
    DecimalFormat usFormat = new DecimalFormat("###,###.000"); 
    
    System.out.println(usFormat.format(111111123456.1227222)); 
    
    
    //3.
    DecimalFormat addPattenFormat = new DecimalFormat(); 
    
    addPattenFormat.applyPattern("##,###.000"); 
    
    System.out.println(addPattenFormat.format(111111123456.1227)); 
    
     
    //4.
    DecimalFormat zhiFormat = new DecimalFormat(); 
    
    zhiFormat.applyPattern("0.000E0000"); 
    
    System.out.println(zhiFormat.format(10000)); 
    
    System.out.println(zhiFormat.format(12345678.345)); 
    
     
    //5.
    DecimalFormat percentFormat = new DecimalFormat(); 
    
    percentFormat.applyPattern("#0.000%"); 
    
    System.out.println(percentFormat.format(0.3052222));

运行结果 ：
    1111,1112,3456.123 
    111,111,123,456.123 
    111,111,123,456.123 
    1.000E0004 
    1.235E0007 
    30.522%

转载自博客:[https://blog.csdn.net/evangel\_z/article/details/7624503][https_blog.csdn.net_evangel_z_article_details_7624503]

[https_blog.csdn.net_baidu_33604078_article_details_78954704]: https://blog.csdn.net/baidu_33604078/article/details/78954704
[https_jingyan.baidu.com_article_6f2f55a156b2d0b5b93e6cc2.html]: https://jingyan.baidu.com/article/6f2f55a156b2d0b5b93e6cc2.html
[https_www.cnblogs.com_tjlgdx_p_6163517.html]: https://www.cnblogs.com/tjlgdx/p/6163517.html
[https_blog.csdn.net_weixin_38610651_article_details_82796317]: https://blog.csdn.net/weixin_38610651/article/details/82796317
[https_blog.csdn.net_js940814_article_details_80186857]: https://blog.csdn.net/js940814/article/details/80186857
[https_blog.csdn.net_evangel_z_article_details_7624503]: https://blog.csdn.net/evangel_z/article/details/7624503