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ISsue with modifying std::cout

chuvak (67)
I have,
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double temp_price;
std::cout << "Price?\n> "; //12345.6789
std::cin >> temp_price;
std::cout << "Price\t\t >> " << std::cout.setf(std::ios::fixed) << std::cout.precision(4) << temp_price << " <<" << std::endl;


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Expected Output:
>>12345.6789<<

Actual output:
>>513612345.6789<<


Any thoughts why this is happening?
JLBorges (13770)
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#include <iostream>
#include <iomanip>

int main()
{
    double temp_price;
    std::cout << "Price?\n> "; //12345.6789
    std::cin >> temp_price;

    // **** don't do this
    // std::cout << "Price\t\t >> " << std::cout.setf(std::ios::fixed) << std::cout.precision(4) << temp_price << " <<" << std::endl;

    // this is fine
    std::cout << "Price\t\t >> " << std::fixed << std::setprecision(4) << temp_price << " <<" << std::endl;

    // this would also have been fine
    std::cout.setf(std::ios::fixed) ;
    std::cout.precision(4) ;
    std::cout << "Price\t\t >> " << std::fixed << std::setprecision(4) << temp_price << " <<" << std::endl;
}


> Any thoughts why this is happening?

std::cout.setf(std::ios::fixed) returns the old format flags (ones before the call to the function).
std::cout.precision(4) returns the old precision (the precision before the function was called).

These two values get printed (if the format flags are of some output streamable type).
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