【c++基础】ifstream的构造函数

公共成员函数：

default (1) ifstream();
initialization (2)
explicit ifstream (const char* filename, ios_base::openmode mode = ios_base::in);
explicit ifstream (const string& filename, ios_base::openmode mode = ios_base::in);
copy (3) ifstream (const ifstream&) = delete;
move (4) ifstream (ifstream&& x);

mode

member constant

stands for

access

in*

input

File open for reading: the ​​internal stream buffer​​

out

output

File open for writing: the ​​internal stream buffer​​

binary

binary

Operations are performed in binary mode rather than text.

ate

at end

The output position starts at the end of the file.

app

append

All output operations happen at the end of the file, appending to its existing contents.

trunc

truncate

Any contents that existed in the file before it is open are discarded.

code

// ifstream constructor.
#include <iostream> // std::cout
#include <fstream> // std::ifstream

int main ()
{
std::ifstream ifs ("test.txt", std::ifstream::in);
char c = ifs.get();
while (ifs.good())
{
std::cout << c;
c = ifs.get();
}
ifs.close();
return 0;
}

 

参考

1.​​cplusplus.com​​;

完