cout

c++ flushing the buffer

点点圈 提交于 2021-02-16 14:59:28
问题 I know there are many buffer questions on here but I can't seem find a clear answer on this. std::cout << "write to screen" << std::endl; I know this code will write to the screen and flush the buffer because of the "endl", but if I wrote this: std::cout << "write to screen"; Wouldn't the buffer be flushed regardless since the text has been outputted to the screen? 回答1: Wouldn't the buffer be flushed regardless since the text has been outputted to the screen? Assuming that you have seen the

Why does removing 'cout' from my function change its result? [closed]

允我心安 提交于 2021-02-16 04:09:32
问题 Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 7 years ago . Improve this question I am an intermediate programmer, writing a program that's probably much to complicated for me. The programs aim is to construct certain 2-d arrays, and has a few different class objects that are communicating with each other in a not-so-simple way. In order to

Really, what's the opposite of “fixed” I/O manipulator?

时光毁灭记忆、已成空白 提交于 2021-02-09 05:50:39
问题 This may be a duplicate of this question, but I don't feel it was actually answered correctly. Observe: #include <iostream> #include <iomanip> using namespace std; int main () { float p = 1.00; cout << showpoint << setprecision(3) << p << endl; } Output: 1.00 Now if we change that line to: cout << fixed << showpoint << setprecision(3) << p << endl; we get: 1.000 And if we use the "opposite" of fixed we get something totally different: cout << scientific << showpoint << setprecision(3) << p <<

Really, what's the opposite of “fixed” I/O manipulator?

只谈情不闲聊 提交于 2021-02-09 05:43:52
问题 This may be a duplicate of this question, but I don't feel it was actually answered correctly. Observe: #include <iostream> #include <iomanip> using namespace std; int main () { float p = 1.00; cout << showpoint << setprecision(3) << p << endl; } Output: 1.00 Now if we change that line to: cout << fixed << showpoint << setprecision(3) << p << endl; we get: 1.000 And if we use the "opposite" of fixed we get something totally different: cout << scientific << showpoint << setprecision(3) << p <<

C++. Why std::cout << char + int prints int value?

白昼怎懂夜的黑 提交于 2021-02-08 21:17:04
问题 Let's say, we have: char x = 'a'; int y = 1; So, if you run: std::cout << x + y; It prints 98 instead of 'b'. As i see from here <<operator has only int parameter implementation. From now on i have 2 questions: After char + int operation what type is returned? Why there is no char parameter implementation, but std::cout << x still works as expected and prints char value? 回答1: Thanks to Fefux, Bo Persson and Matti Virkkunen answers are: From CPP Reference: Implicit conversions: arithmetic

C++. Why std::cout << char + int prints int value?

送分小仙女□ 提交于 2021-02-08 21:10:39
问题 Let's say, we have: char x = 'a'; int y = 1; So, if you run: std::cout << x + y; It prints 98 instead of 'b'. As i see from here <<operator has only int parameter implementation. From now on i have 2 questions: After char + int operation what type is returned? Why there is no char parameter implementation, but std::cout << x still works as expected and prints char value? 回答1: Thanks to Fefux, Bo Persson and Matti Virkkunen answers are: From CPP Reference: Implicit conversions: arithmetic

C++. Why std::cout << char + int prints int value?

廉价感情. 提交于 2021-02-08 21:04:42
问题 Let's say, we have: char x = 'a'; int y = 1; So, if you run: std::cout << x + y; It prints 98 instead of 'b'. As i see from here <<operator has only int parameter implementation. From now on i have 2 questions: After char + int operation what type is returned? Why there is no char parameter implementation, but std::cout << x still works as expected and prints char value? 回答1: Thanks to Fefux, Bo Persson and Matti Virkkunen answers are: From CPP Reference: Implicit conversions: arithmetic

Printing uint8_t variables using std::cout in C++ [duplicate]

余生颓废 提交于 2021-02-08 10:33:50
问题 This question already has answers here : uint8_t can't be printed with cout (8 answers) Closed 5 years ago . In the following code, it appears that std::cout does not print the variable of type uint8_t properly. int main() { uint8_t var = 16; std::cout << "value: " << var << std::endl; } output: value: I don't have problem with similar uintX_t types. I know I'm missing something here, but I can't figure what it is. 回答1: uint8_t maps to unsigned char on most systems. As the result, the

Printing uint8_t variables using std::cout in C++ [duplicate]

杀马特。学长 韩版系。学妹 提交于 2021-02-08 10:31:26
问题 This question already has answers here : uint8_t can't be printed with cout (8 answers) Closed 5 years ago . In the following code, it appears that std::cout does not print the variable of type uint8_t properly. int main() { uint8_t var = 16; std::cout << "value: " << var << std::endl; } output: value: I don't have problem with similar uintX_t types. I know I'm missing something here, but I can't figure what it is. 回答1: uint8_t maps to unsigned char on most systems. As the result, the

Display a number decimal format instead as an exponential in cout

自闭症网瘾萝莉.ら 提交于 2021-02-05 11:56:21
问题 I calculated a total of floats and I got a number like 509990e-405 . I'm assuming this is the short version; how can I cout this as a full number? cout << NASATotal << endl; is what I have now. 回答1: You can force the output to be not in scientific notation, and to have the sufficient precision to show your small number. #include <iomanip> // ... long double d = 509990e-405L; std::cout << std::fixed << std::setprecision(410) << d << std::endl; Output: 0