C ++十六进制控制台输出翻倍需要解决

Question

my code:

#include <iostream>
#include <iomanip> 
using namespace std;

int main() {
    double A = 100.35;
    cout.precision(0);
    cout << std::hexfloat << std::fixed << std::left << A << endl;
    return 0;
}

Current output: 100

my expected output: x64

Explanation: I want to print the hex value of decimal part of double. But I have been unsuccessful in getting this. need help. Any help in this direction will be appreciated.

Answer 1

What you're asking for is simply not possible. std::hex (the output you're looking for) only works for integral arguments, and std::hexfloat uses an undesirable format. You need to cast or round.

#include <iostream>
#include <iomanip> 
#include <cmath>
using namespace std;

int main() {
    double A = 100.35;
    cout.precision(0);
    cout << std::hex << std::showbase << std::lround(A) << endl;
    return 0;
}