Why does this happen? This has little to do with the input you provided yourself but rather with the default behavior std::getline() has. When you provided your input for the age (std::cin >> age), you not only submitted the following characters, but also an implicit newline was appended to the stream when you typed Enter: … Read more
you need to #include <iostream> or #include <ios> then when required: std::ios_base::fmtflags f( cout.flags() ); //Your code here… cout.flags( f ); You can put these at the beginning and end of your function, or check out this answer on how to use this with RAII.
The word “stream” has been chosen because it represents (in real life) a very similar meaning to what we want to convey when we use it. Let’s forget about the backing store for a little, and start thinking about the analogy to a water stream. You receive a continuous flow of data, just like water … Read more
The word “stream” has been chosen because it represents (in real life) a very similar meaning to what we want to convey when we use it. Let’s forget about the backing store for a little, and start thinking about the analogy to a water stream. You receive a continuous flow of data, just like water … Read more
Not answering the specifics of your question so much as the title: the 2006 Technical Report on C++ Performance has an interesting section on IOStreams (p.68). Most relevant to your question is in Section 6.1.2 (“Execution Speed”): Since certain aspects of IOStreams processing are distributed over multiple facets, it appears that the Standard mandates an … Read more
Just telling you about one other possibility: I like using friend definitions for that: namespace Math { class Matrix { public: […] friend std::ostream& operator<< (std::ostream& stream, const Matrix& matrix) { […] } }; } The function will be automatically targeted into the surrounding namespace Math (even though its definition appears within the scope of … Read more
The easiest way is probably to create an std::bitset representing the value, then stream that to cout. #include <bitset> … char a = -58; std::bitset<8> x(a); std::cout << x << ‘\n’; short c = -315; std::bitset<16> y(c); std::cout << y << ‘\n’;
You can set the precision directly on std::cout and use the std::fixed format specifier. double d = 3.14159265358979; cout.precision(17); cout << “Pi: ” << fixed << d << endl; You can #include <limits> to get the maximum precision of a float or double. #include <limits> typedef std::numeric_limits< double > dbl; double d = 3.14159265358979; cout.precision(dbl::max_digits10); … Read more
I’m surprised that everyone in this question claims that std::cout is way better than printf, even if the question just asked for differences. Now, there is a difference – std::cout is C++, and printf is C (however, you can use it in C++, just like almost anything else from C). Now, I’ll be honest here; … Read more
Because iostream::eof will only return true after reading the end of the stream. It does not indicate, that the next read will be the end of the stream. Consider this (and assume then next read will be at the end of the stream): while(!inStream.eof()){ int data; // yay, not end of stream yet, now read … Read more