Decimal to hex conversion c++ built-in function

问题:

Is there a built-in function in c++ that would take a decimal input from a user and convert it to hex and vice versa?? I have tried it using a function I've written but I was wondering if there is a built-in one to minimize the code a little bit. Thanks in advance.

回答1:

Decimal to hex :-

std::stringstream ss;
ss<< std::hex << decimal_value; // int decimal_value
std::string res ( ss.str() );

std::cout << res;

Hex to decimal :-

std::stringstream ss;
ss  << hex_value ; // std::string hex_value
ss >> std::hex >> decimal_value ; //int decimal_value

std::cout << decimal_value ;

Ref: std::hex, std::stringstream

回答2:

Many compilers support the itoa function (which appears in the POSIX standard but not in the C or C++ standards). Visual C++ calls it _itoa.

#include <stdlib.h>

char hexString[20];
itoa(value, hexString, 16);

Note that there is no such thing as a decimal value or hex value. Numeric values are always stored in binary. Only the string representation of the number has a particular radix (base).

Of course, using the %x format specifier with any of the printf functions is good when the value is supposed to be shown in a longer message.

回答3:

include

using namespace std;

int DecToHex(int p_intValue)
{
    char *l_pCharRes = new (char);
    sprintf(l_pCharRes, "%X", p_intValue);
    int l_intResult = stoi(l_pCharRes);
    cout << l_intResult<< "\n";
    return l_intResult;
}

int main()
{
    int x = 35;
    DecToHex(x);
    return 0;
}