将二进制位集转换为十六进制 (C++)
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Convert binary bitset to hexadecimal (C++)
提问by navig8tr
Is there a simple way to convert a binary bitset to hexadecimal? The function will be used in a CRC class and will only be used for standard output.
有没有一种简单的方法可以将二进制位集转换为十六进制？该函数将在 CRC 类中使用，并且仅用于标准输出。
I've thought about using to_ulong() to convert the bitset to a integer, then converting the integers 10 - 15 to A - F using a switch case. However, I'm looking for something a little simpler.
我想过使用 to_ulong() 将位集转换为整数，然后使用 switch case 将整数 10 - 15 转换为 A - F。但是，我正在寻找更简单的东西。
I found this code on the internet:
我在网上找到了这段代码：
#include <iostream>
#include <string>
#include <bitset>
using namespace std;
int main(){
string binary_str("11001111");
bitset<8> set(binary_str);
cout << hex << set.to_ulong() << endl;
}
It works great, but I need to store the output in a variable then return it to the function call rather than send it directly to standard out.
它工作得很好，但我需要将输出存储在一个变量中，然后将其返回给函数调用，而不是直接将其发送到标准输出。
I've tried to alter the code but keep running into errors. Is there a way to change the code to store the hex value in a variable? Or, if there's a better way to do this please let me know.
我试图改变代码，但一直遇到错误。有没有办法更改代码以将十六进制值存储在变量中？或者，如果有更好的方法来做到这一点，请告诉我。
Thank you.
谢谢你。
采纳答案by dasblinkenlight
You can send the output to a std::stringstream, and then return the resultant string to the caller:
您可以将输出发送到 a std::stringstream，然后将结果字符串返回给调用者：
stringstream res;
res << hex << uppercase << set.to_ulong();
return res.str();
This would produce a result of type std::string.
这将产生类型为 的结果std::string。
回答by technosaurus
Here is an alternative for C:
这是 C 的替代方案：
unsigned int bintohex(char *digits){
unsigned int res=0;
while(*digits)
res = (res<<1)|(*digits++ -'0');
return res;
}
//...
unsigned int myint=bintohex("11001111");
//store value as an int
printf("%X\n",bintohex("11001111"));
//prints hex formatted output to stdout
//just use sprintf or snprintf similarly to store the hex string
回答by dumb_pawn
Here is the easy alternative for C++:
这是 C++ 的简单替代方案：
bitset <32> data;
/*Perform operation on data*/
cout << "data = " << hex << data.to_ulong() << endl;
bitset <32> data;
/*Perform operation on data*/
cout << "data = " << hex << data.to_ulong() << endl;
