c++初級

1.不同進制數的輸出

#include

using namespace std;

int main()

{

int num;

cout<<“請輸入一個整型數：”;

cin>>num;

cout<<“八進制數是：”<<oct<<num<<endl;

cout<<“十進制數是：”<<dec<<num<<endl;

cout<<“十六進制數是：”<<hex<<num<<endl;

return 0;

}

2.get函數和getline函數

#include

using namespace std;

int main()

{

char s1,s2,s3[50],s4[50];

cout<<“請輸入一個字元：”;

cout<<cin.get()<<endl;//讀取一個字元的ASCII碼值

cin.get();//提取換行符

cout<<“請輸入兩個字元：”;

cin.get(s1).get(s2);

cout<<s1<<s2<<endl;

cin.get();

cout<<“請輸入一個字元串：”;

cin.get(s3,50);

cout<<s3<<endl;

cin.get();

cout<<“請輸入一個字元串：”;

cin.getline(s4,50);

cout<<s4<<endl;

return 0;

}

3.read函數

#include

using namespace std;

int main()

{

char ch[100];

char *str=ch;

cout<<“read 函數的使用：”<<endl;

cout<<“請輸入字元：”<<endl;

cin.read(str,100);

str[cin.gcount()]=’\0’;//這一句要有，否則會出現亂碼

cout<<str<<endl;

}

4.put函數和write函數應用

#include

#include<string.h>

using namespace std;

int main()

{

char s1[100],s2[50]=“Happy new year”;

cout<<“put 和 writer函數的應用!”<<endl;

cout<<‘M’<<endl;

cout.put(‘M’);

cout.put(’\n’);

cout<<“請輸入一串字元：”;

cin.read(s1,100);

cout.write(s1,5)<<endl;

cout.write(s2,strlen(s2))<<endl;

return 0;

}

5.檔案輸出流的應用

#include

#include

using namespace std;

int main()

{

char str[100];

ofstream myFout(“F:\趙傑\c++程式\example.txt.txt”,ios::out);

cout<<“檔案輸出流的應用！”<<endl;

if(myFout.fail())

{

cout<<“This file dose not exist!”<<endl;

return 0;

}

else

{

cout<<“Open this file!”<<endl;

}

for(int i=0;i<4;i++)

{

cin>>str;

myFout<<str<<endl;

}

myFout.close();

return 0;

}

6.檔案輸入流的應用

#include

#include

using namespace std;

int main()

{

char str[100];

ifstream myFin(“F:\趙傑\c++程式\example.txt.txt”,ios::in);

cout<<“檔案輸入流的應用！”;

if(myFin.fail())

{

cout<<“This file does not exist!”<<endl;

return 0;

}

else

{

cout<<“Open the file!”<<endl;

}

for(int i=0;i<4;i++)

{

myFin>>str;

cout<<str<<endl;

}

myFin.close();

return 0;

}

7.将FileRead檔案内容寫到FileWrite檔案

#include

#include

using namespace std;

int main()

{

char str;

fstream FileRead,FileWrite;

FileRead.open(“F:\趙傑\c++程式\example.txt.txt”,ios::in);

FileWrite.open(“F:\趙傑\c++程式\FileWrite.txt”,ios::out);

while(!FileRead.eof())//判斷是否讀完檔案

{

FileRead.read(&str,1);

cout<<str;

FileWrite.write(&str,1);

}

FileRead.close();

FileWrite.close();

return 0;

}