如何在C ++中将文本追加到文本文件？

Question

如何在C ++中将文本追加到文本文件？如果不存在则创建新的，如果存在则追加。

Answer 1

#include <fstream>int main() {&nbsp;&nbsp;&nbsp; std::ofstream outfile;&nbsp; outfile.open("test.txt", std::ios_base::app);&nbsp; outfile << "Data";&nbsp;&nbsp; return 0;}

Answer 2

#include <fstream>&nbsp;#include <iostream>&nbsp;FILE * pFileTXT;&nbsp;int counterint main(){&nbsp;pFileTXT = fopen ("aTextFile.txt","a");// use "a" for append, "w" to overwrite, previous content will be deleted&nbsp;for(counter=0;counter<9;counter++)&nbsp;fprintf (pFileTXT, "%c", characterarray[counter] );// character array to file&nbsp;fprintf(pFileTXT,"\n");// newline&nbsp;for(counter=0;counter<9;counter++)&nbsp;fprintf (pFileTXT, "%d", digitarray[counter] );&nbsp; &nbsp; // numerical to file&nbsp;fprintf(pFileTXT,"A Sentence");&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;// String to file&nbsp;fprintf (pFileXML,"%.2x",character);&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; // Printing hex value, 0x31 if character= 1&nbsp;fclose (pFileTXT); // must close after opening&nbsp;return 0;}