java中的字符型数据 Java 字符数据类型

Java数据类型教程 - Java字符数据类型

Character类的一个对象包装一个char值。

字符类包含isLetter()和isDigit()方法来检查字符是否为字母和数字。

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创建对象。

charValue()方法返回对象包装的char。

例子

以下代码显示了如何创建Character对象以及如何使用它们的一些方法：

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));

  }
}

上面的代码生成以下结果。