Java编程思想学习笔记（—）
Java编程思想学习笔记（—）
???
?
（美） Bruce Eckel 著 《Java编程思想》部分学习日记（随手记录的笔记）
?
???????? 代码：
?
public class JavaTest { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub Dog spot = new Dog(); spot.name = "zengxiao"; spot.say = "汪汪"; Dog spot1 =new Dog(); spot1.name ="zengxiao"; spot1.say="汪汪"; Integer intNum =new Integer(47); Integer intNum1 =new Integer(47); System.out.println(intNum==intNum1); System.out.println(intNum.equals(intNum1)); System.out.println(spot==spot1); System.out.println(spot.equals(spot1)); }}class Dog { String name; String say;}?输出的结果就是：
? false
? true
? false
? false
??????? 代码：
public class JavaTest { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub int i1= 0x2f; System.out.println(Integer.toBinaryString(i1)); long l1 =02567; System.out.println(Long.toBinaryString(l1)); }}? ?把十六进制和八进制转化成二进制的数时用，toBinaryString
?
?
生成一个随机小写字母的方法：
?
Random rnd = new Random();char c =(char)(rnd.nextInt(26)+'a');
?
??? 生成随机数的方法：
?
Random rnd = new Random(); ArrayList<Integer> listInt = new ArrayList(); int i = 0; while (i < 25) { int j =rnd.nextInt(500); if (!listInt.contains(j)) { listInt.add(j); i++; } } for (Integer integer : listInt) { System.out.println(integer); }?
??? Arrays.toString()将产生一维数组的可打印版本
?
public class JavaTest { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub Random rndRandom =new Random(); int[] intNum =new int[rndRandom.nextInt(20)]; System.out.println(intNum.length); for (int i = 0; i < intNum.length; i++) { intNum[i]=rndRandom.nextInt(200); } System.out.println(Arrays.toString(intNum)); }}??
?
??代码：
public class JavaTest { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub for (Spiciness s : Spiciness.values()) { System.out.println(s+",ordinal"+s.ordinal()); } } public enum Spiciness { Not,mild,zengxiao,zeng,xiao }}??