Java字符数据类型

心已赠人 2022-09-30 12:51 178阅读 0赞

`Character`类的一种对象包装一个`char`值的包装类。`Character`类包含`isLetter()`和`isDigit()`方法来检查字符是否为字母或数字。

`toUpperCase()`和`toLowerCase()`方法将字符转换为大写和小写。该类提供了一个构造函数和一个工厂`valueOf()`方法来从`char`类型值创建对象。`charValue()`方法返回对象包装的`char`类型值。

## 示例 ##

以下代码显示了如何创建`Character`对象以及如何使用它的一些方法：

public class Main { public static void main(String[] args) { // Using the constructor Character c1 = new Character('A'); // Using the factory method - preferred Character c2 = Character.valueOf('2'); Character c3 = Character.valueOf('-'); // Getting the wrapped char values char cc1 = c1.charValue(); char cc2 = c2.charValue(); char cc3 = c3.charValue(); System.out.println("c1 = " + c1); System.out.println("c2 = " + c2); System.out.println("c3 = " + c3); // Using some Character class methods on c1 System.out.println("isLowerCase c1 = " + Character.isLowerCase(cc1)); System.out.println("isDigit c1 = " + Character.isDigit(cc1)); System.out.println("isLetter c1 = " + Character.isLetter(cc1)); System.out.println("Lowercase of c1 = " + Character.toLowerCase(cc1)); // Using some Character class methods on c2 System.out.println("isLowerCase c2 = " + Character.isLowerCase(cc2)); System.out.println("isDigit c2 = " + Character.isDigit(cc2)); System.out.println("isLetter c2 = " + Character.isLetter(cc2)); System.out.println("Lowercase of c2 = " + Character.toLowerCase(cc2)); System.out.println("Uppercase of c3 = " + Character.toUpperCase(cc3)); } } 
      
       Java

上面的代码生成以下结果。

c1 = A c2 = 2 c3 = - isLowerCase c1 = false isDigit c1 = false isLetter c1 = true Lowercase of c1 = a isLowerCase c2 = false isDigit c2 = true isLetter c2 = false Lowercase of c2 = 2 Uppercase of c3 = -