Thinking in Java笔记1

（第1、2章笔记）

 

package com;import java.math.BigInteger;/** The first example program.* Lists system information on current machine.* @author Haibo Zhang* @author [e-mail]* @version 1.0*/public class Test {/** Sole entry point to class & application* @param args array of string arguments* @return No return value* @exception exceptions No exceptions thrown*/boolean flag;//作为类成员，java为主类型设置默认值，boolean为falsestatic int s;//静态成员可用类名直接操作，如：Test.s = 1;静态成员函数亦如此public static void main(String[] args) {// TODO Auto-generated method stubCharacter a = new Character('a');//于堆中(与/*1*/行比较)BigInteger b = new BigInteger("1");//创建句柄b，主类型则不是句柄System.out.println("a = "+a);System.out.println("b = " + b);/*1*/int c = 2;//与堆栈中if(true){//int c = 3; //illegal！Integer d = new Integer(1);//与/*2*/行比较，if后句柄d自动消失}/*2*/Integer d = new Integer(1);//若将此行放至if前，则报错Test test1 = new Test();}Test(){System.out.println("flag = " + flag);}} 

 

运行结果：

 

a = a
b = 1
flag = false