JavaSE8基础 Character.toXXX 大写字母与小写字母的转换

os ：windows7 x64
    jdk：jdk-8u131-windows-x64
    ide：Eclipse Oxygen Release (4.7.0)
    
    
code：

package jizuiku3;

public class Demo101 {
	public static void main(String[] args) {
		char c = ‘a‘;
		char c2 = Character.toUpperCase(c);
		System.out.println(c2);

		char d = ‘A‘;
		char d2 = Character.toLowerCase(d);
		System.out.println(d2);

		//上合法，下则反

		char e = ‘1‘;
		char e2 = Character.toLowerCase(e);
		System.out.println(e2);

		char f = ‘!‘;
		char f2 = Character.toLowerCase(f);
		System.out.println(f2);

	}
}

result：

view：

　　要想知道为啥有此特性？ 还要看源代码！