Java字符数据类型

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 = Ac2 = 2c3 = -isLowerCase c1    = falseisDigit c1    = falseisLetter c1    = trueLowercase of  c1    = aisLowerCase c2    = falseisDigit c2    = trueisLetter c2    = falseLowercase of  c2    = 2Uppercase of  c3    = -