Large floating-point numbers are printed in scientific notation by default; small floating-point numbers can be forced to print in scientific notation.
#include <iostream>
using namespace std;
int main()
{
cout << 23.5 << endl;
cout << 1000000.0 << endl;
cout << 6.0221413e23 << endl;
cout << endl;
cout << fixed << 23.5 << endl;
cout << fixed << 1000000.0 << endl;
cout << fixed << 6.0221413e23 << endl;
cout << endl;
cout << scientific << 23.5 << endl;
cout << scientific << 1000000.0 << endl;
cout << scientific << 6.0221413e23 << endl;
return 0;
}
Output:
23.5 1e+006 6.02214e+023 23.500000 1000000.000000 602214130000000020000000.000000 2.350000e+001 1.000000e+006 6.022141e+023