如何在C ++中打印出二进制的unsigned int？

Question

I am trying to print out an unsigned value in binary in C++. I have found many hacks for this task such as

http://www.java2s.com/Tutorial/Cpp/0040__Data-Types/Printinganunsignedintegerinbits.htm

However, I feel that there should be a much more straightforward way, perhaps with sprintf . After all, there are very straightforward ways to print a value in hex or octal.

Answer 1

Simple - Use STL bitset :

eg

bitset<10> n (120ul); // 10 bits in this case
cout << n.to_string() << endl;

Answer 2

printf familiy does not support base-2 printing. You need to use a custom or non-standard function, such as itoa (just set the base/radix to 2).