How to Implement C ++ file stream operations

In actual programming, C ++ is a simple operation for file operations. You can use some simple examples to fully master this application skill, it also helps your program development in actual programming. Next let's take a look at the application skills related to file stream operations in C ++.

File writing for C ++ file stream operations:

 
 

  
  
# Include <fstream>
  
  
# Include <iostream>
  
  
Using namespace std;
  
  
Int main (){
  
  
String str;
  
  
Ofstream out ("d.txt ");
  
  
Str = "Moonlight in front of bed \ n suspected to be frost on the ground \ n raised his head to the moon \ n bowed his head to his hometown \ n ";
  
  
Out <str <endl;
  
  
Return 0;
  
  
}
 
 

C ++ file stream operations for file reading:

 
 

  
  
#include < fstream> 
  
  
#include < iostream>   
  
  
using namespace std;  
  
  
int main(){  
  
  
ifstream in("a.txt");  
  
  
for(string str;getline(in,str);)  
  
  
cout< < str< < "\n";  
  
  
return 0;   
  
  
} 
 
 

File Replication in C ++ file stream operations

 
 

  
  
# Include <fstream>
  
  
# Include <iostream>
  
  
Using namespace std;
  
  
Int main (){
  
  
Ifstream in ("a.txt ");
  
  
Ofstream out ("B .txt ");
  
  
For (string str; getline (in, str );)
  
  
Out <str <endl;
  
  
Cout <"file copied !!! ";
  
  
Return 0;
  
  
}
 
 

Screening Method for Determining prime numbers

 
 

  
  
#include < iostream> 
  
  
#include < vector> 
  
  
#include < fstream> 
  
  
using namespace std;  
  
  
int main(){  
  
  
vector< int> prime(10000,1);  
  
  
for(int i=2;i< 100;++i)  
  
  
if(prime[i])  
  
  
for(int j=i;i*j< 10000;++j)  
  
  
prime[i*j]=0;  
  
  
ifstream in("c.txt");  
  
  
for(int a;in>>a && a>1 && a< 10000;)  
  
  
cout< < a< < " is "< < (prime[a]?"":"not ")< < " a prime.\n";   
  
  
} 
 
 

In the c.txt file, write a series of integers smaller than 10000 and wrap the line to determine the prime number, because it also involves the reading operation of the file, so it is also given.

I feel that the C ++ file stream is operating esay! It is more complicated to read files from Java.