Java字符數據類型
Character
類的一種對象包裝一個char
值的包裝類。Character
類包含isLetter()
和isDigit()
方法來檢查字符是否爲字母或數字。
toUpperCase()
和toLowerCase()
方法將字符轉換爲大寫和小寫。該類提供了一個構造函數和一個工廠valueOf()
方法來從char
類型值創建對象。charValue()
方法返回對象包裝的char
類型值。
示例
以下代碼顯示瞭如何創建Character
對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));
}
}
上面的代碼生成以下結果。
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 = -