C++文件讀寫代碼分享
編寫一個(gè)程序,統(tǒng)計(jì)data.txt文件的行數(shù),并將所有行前加上行號(hào)后寫到data1.txt文件中。
算法提示:
行與行之間以回車符分隔,而getline()函數(shù)以回車符作為終止符。因此,可以采用getline()函數(shù)讀取每一行,再用一個(gè)變量i計(jì)算行數(shù)。
(1)實(shí)現(xiàn)源代碼
#include <iostream> #include <fstream> #include <string> #include <sstream> using namespace std; int coutFile(char * filename,char * outfilename) { ifstream filein; filein.open(filename,ios_base::in); ofstream fileout; fileout.open(outfilename,ios_base::out); string strtemp; int count=0; while(getline(filein,strtemp)) { count++; cout<<strtemp<<endl; fileout<<count<<" "<<strtemp<<endl; } filein.close(); fileout.close(); return count; } void main() { cout<<coutFile("c:\\data.txt","c:\\data1.txt")<<endl; }
再來一個(gè)示例:
下面的C++代碼將用戶輸入的信息寫入到afile.dat,然后再通過程序讀取出來輸出到屏幕
#include <fstream> #include <iostream> using namespace std; int main () { char data[100]; // open a file in write mode. ofstream outfile; outfile.open("afile.dat"); cout << "Writing to the file" << endl; cout << "Enter your name: "; cin.getline(data, 100); // write inputted data into the file. outfile << data << endl; cout << "Enter your age: "; cin >> data; cin.ignore(); // again write inputted data into the file. outfile << data << endl; // close the opened file. outfile.close(); // open a file in read mode. ifstream infile; infile.open("afile.dat"); cout << "Reading from the file" << endl; infile >> data; // write the data at the screen. cout << data << endl; // again read the data from the file and display it. infile >> data; cout << data << endl; // close the opened file. infile.close(); return 0; }
程序編譯執(zhí)行后輸出如下結(jié)果
$./a.out Writing to the file Enter your name: Zara Enter your age: 9 Reading from the file Zara 9
以上所述就是本文的全部?jī)?nèi)容了,希望大家能夠喜歡。
相關(guān)文章
vs運(yùn)行時(shí)報(bào)C4996代碼錯(cuò)誤的問題解決
C4996錯(cuò)誤的意思:是VS覺得strcpy這函數(shù)不安全,建議你使更安全的函數(shù),那么如何解決呢,本文主要介紹了vs運(yùn)行時(shí)報(bào)C4996代碼錯(cuò)誤的問題解決,感興趣的可以了解一下2024-01-01C++重載運(yùn)算符實(shí)現(xiàn)分?jǐn)?shù)加減乘除
這篇文章主要為大家詳細(xì)介紹了C++重載運(yùn)算符實(shí)現(xiàn)分?jǐn)?shù)加減乘除,文中示例代碼介紹的非常詳細(xì),具有一定的參考價(jià)值,感興趣的小伙伴們可以參考一下2021-06-06