java iostream,includeiostream

1,includeiostreamPeople类里面有一行Date birth;这个调用的是Date的默认构造函数!【java iostream,includeiostream】
2,文件流中IOStreamDemojava是什么东西一个系统文件demo是“例子”的意思 。这个java文件是一个由用户自己定义的一个java文件,应该在开发包中可以找到 。一个类 。。。应该是某个示例吧 。。。
3,关于iostream#include <iostream>后要加一个using namespace std;#include <iostream>using namespace std;int main()std::cout<<"我喜欢c++\n";return 0;}#include <iostream.h>int main() cout<<"我喜欢c++\n";return 0;}
4 , systemcopy file1 file2package cnn;import java.io.*;public class Copy {public static void main(String[] args) {Copy a = new Copy();System.out.println("请输入来源文件的路径:");String infn = a.getPath();System.out.println("请输入目标文件的路径:");String outfn = a.getPath();File in = new File(infn);File out = new File(outfn);if(in.isFile()&&in.canRead()){try{RandomAccessFile infile = new RandomAccessFile(infn,"r");RandomAccessFile outfile = new RandomAccessFile(outfn,"rw");System.out.println("file is found !");System.out.println("file name:"+in.getName());System.out.println("Absolute Path:"+in.getAbsolutePath());System.out.println("file length:"+in.length());while(infile.getFilePointer()相对路径起始路径是你这个程序的工作路径首先要知道你的程序的工作路径和文件路径的关系5 , JAVA编程import java.util.*;public class DiGuiTestpublic static void main(String[] args)Scanner input=new Scanner(System.in);System.out.print("输入一个起始数字:");int start=input.nextInt();System.out.print("\n输入一个终止数字:");int end=input.nextInt();int i=sum(start+1,end-1);System.out.print("\n和是:"+i); } private static int sum(int start,int n)if(n==start)return start;elsereturn sum(start,(n-1))+n; }}package com.test;import java.util.Scanner;public class test/*** @param args*/ public static void main(String[] args)Scanner in =new Scanner(System.in);System.out.println("请输入一个起始数字:");int start = in.nextInt();System.out.println("请输入一个结束数字:");int end = in.nextInt();int result=0;int i =0;for(i=start+1;i<end;i++)result+=i;//System.out.println(start+"到"+end+"之间数字的累加结果为:"+result);}System.out.println(start+"到"+end+"之间数字的累加结果为:"+result); }}用c++编一个 , 其实都差不多#includes<iostream>void main()int max,min;cout<<"请输入2个数字(大的在前面)“<<endl;cin>>max>>min;sum=min;for(int i=min;i<max;i++)sum+=i;}cout<<sum;}public class Sumprivate int First; private int Last; public Sum(int first,int last)this.First=first;this.Last=last; } public int Sum()return ((this.First+this.Last)*(this.Last-this.First+1))/2; }}public class Testpublic static void main(String[] args)Sum s=new Sum(1,2);System.out.println(s.Sum()); }}

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