signed

问题 I want to convert a hex string to a 32 bit signed integer in C++. So, for example, I have the hex string \"fffefffe\". The binary representation of this is 11111111111111101111111111111110. The signed integer representation of this is: -65538. How do I do this conversion in C++? This also needs to work for non-negative numbers. For example, the hex string \"0000000A\", which is 00000000000000000000000000001010 in binary, and 10 in decimal. 回答1: use std::stringstream unsigned int x; std:

问题 In the book \"Complete Reference of C\" it is mentioned that char is by default unsigned. But I am trying to verify this with GCC as well as Visual Studio. It is taking it as signed by default. Which one is correct? 回答1: The book is wrong. The standard does not specify if plain char is signed or unsigned. In fact, the standard defines three distinct types: char , signed char , and unsigned char . If you #include <limits.h> and then look at CHAR_MIN , you can find out if plain char is signed