iomanip.h (see iostream.h)

Symbols Defined: setw, setprecision, setiosflags, resetiosflags, setfill, hex, oct, dec, ios::left, ios::scientific, ios::fixed, ios::right, ios::in, ios::out, ios::beg, ios::cur, ios::end

Usage: cout<<hex<<58<<oct<<58<< dec<<58;
Output: 3a 72 58

hexcauses the numbers that follow to be printed in hexadecimal using the digits 0-9 and a-f. Once set, a number-base manipulator remains in effect until overridden by another manipulator.
octcauses the numbers that follow to be printed in octal using the digits 0-7.
dec (the default setting)causes the numbers that follow to be printed in decimal using the digits 0-9.

Usage: cout<<setiosflags(ios::left)<<setw(10)<<56<<setw(10)<<82<<endl;

Output:5682

Usage: cout<<setiosflags(ios::right)<<setw(10)<<56<<setw(10)<<82<<endl;

Output:

56

82

setw(8) (the default is 0)sets the width of the space in which the next number is output. If the width is zero, only the number is output with no leading or trailing blanks.
setiosflags(ios::left|ios::fixed)the flags are named ios::left etc. Flags may be combined as in setiosflags(ios::left|ios::fixed). Once set, the effect of a flag remains active until a reset or a different flag is set.
ios::leftonly affects the next number printed. It will be left-justified on output.
ios::right (the default setting)only affects the next number printed. It will be right-justified on output.

Usage:
cout<<setiosflags(ios::fixed)<<setprecision(3)<<setw(10)<<56.11233<<setw(10)<<setprecision(5)<<56.11233<<endl;
cout<<setiosflags(ios::scientific)<<setprecision(3)<<setw(10)<<56.11233<<setw(10)<<setprecision(5)<<56.11233<<endl;

Output:

56.112
5.611e+01

56.11233
5.61123e+01

ios::fixedcauses the numbers that follow to be printed without an exponent, if possible. Once set, a number-base manipulator remains in effect until overridden by another manipulator.
ios::scientificcauses the numbers that follow to be printed in scientific notation e.g. normalized 1.56e-03 is the same as 0.00156.
setprecision(3) (3 is the default)causes three digits to be printed to the right of the decimal point.