字符串与字符或者字符大小写与数字之间的转换

//字符大小写相差32小写比大写大32，字符1与数字1相差48，数字1与小写字符相差97与大写字符相差65
		char a='A';
		char b='a';
		int a1=a;
		int a2=b;
		System.out.println(a1);
		System.out.println(a2);
		char c='1';
		int d=1;
		int e=c;
		char f=65;
		int g='c'-'a';
		System.out.println(d);
		System.out.println(e);
		System.out.println(f);
		System.out.println(g);