How to output a float neither in scientific, nor in fixed point notation in std::cout?

#include <iostream>

int main()
{
    float test = 12535104400;

    std::cout << test;

    std::cin.get();
    return 0;
}

//on msvc 2010 this ouputs:  1.25351e+0开发者_如何学编程10

I would like it to output just "12535104400" or in other words, the human readable format which has no leading zeros, but outputs the full value of a number.

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The particular number cannot be accurately represented, for example try the following:

  float v = 12535104400;
  cout.precision(0);
  cout << fixed << v << endl;

You'll see it outputs: 12535104512

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You will need to include <iomanip> :

int main()
{
    const double test = 12535104400;

    std::cout << std::fixed << std::setprecision(0) << test;

    std::cin.get();
    return 0;
}

• std::fixed is the manipulator which uses fixed-point precision (not scientific notation)
• std::setprecision(0) sets how many digits to display after the decimal point

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float test = 12535104400;

This should be a compiler error if your compiler doesn't support long long and int is 32-bit. Use floating literals instead of integer literals e.g 1234.0f vs 1234

#include <iostream>
#include <iomanip>
int main()
{
    float test = 12535104400.0f;

    std::cout << std::setiosflags(ios::fixed) << std::setprecision(0) << test;

    std::cin.get();
    return 0;
}

should print what you want. But beware that float isn't that precise

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You are out of luck, 4-byte float can store cca 7 digits. Use double or long for such numbers.

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In order to format the output in iostream, you'll need manipulators

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If you're willing to lose precision, you can typecast it to an integer.

cout << int(test);

or

cout << (int)test;