c The function contained in the iomanip h header file

It's the Io stream control header file, just like the formatted output inside C.

Here are some commonly used functions:

dec is set to a base of 10 which is equivalent to"%d"

The hex base is 16 equivalent to"%x"

The oct base is 8 which is equivalent to"%o"

setfill(c) sets the fill character to c

setprecision(n) sets the display decimal precision to n digits.

setw(n) sets the field width to n characters.

setiosflags(ios::fixed) Fixed floating-point display.

setiosflags(ios::scientific) exponential representation.

setiosflags(ios::left) is left-aligned.

setiosflags(ios::right) is right-aligned.

setiosflags(ios::skipws ignores leading whitespace.

setiosflags(ios::uppercase) uppercase output of hexadecimal numbers.

setiosflags(ios::lowercase) 16decimal lowercase output.

setiosflags(ios::showpoint) forces the display of a decimal point.

setiosflags(ios::showpos) forces the display of symbols.

Example: include

#include

int main()

cout<<

In C++ programs, you will often see the following header file.

#include

IO stands for Input Output, and Manip is an abbreviation for Manipulator (on C++ it only works by input abbreviations.) ）

The role of iomanip:

It is mainly used for some manipulation operators such as cin, cout, etc., such as setfill, setw, setbase, setprecision, etc. It's the IO flow control header file, just like the formatted output inside C. Here are some common control functions:

dec is set to a base of 10 which is equivalent to"%d"

The hex base is 16 equivalent to"%x"

The oct base is 8 which is equivalent to"%o"

setfill( 'c') sets the padding character to c

setprecision(n) sets the display decimal precision to n digits.

setw(n) sets the field width to n characters.

The meaning of this controller is to ensure that the output width is n. Such as:

cout <1 10100 (right-aligned by default) setw(3) does not work when the output length is greater than 3 (<< 1000).

setw(n) usage: In layman's terms, it is the preset width.

Such as cout<

#include

using namespace std;

int main()

This header file is embedded only when you need to use functions that control the data output format.

e.g. int a=123456;

cout<

Add include

using namespace std;

Then you can use the functions in your program.