The role of the iomanip header file

The following header file is often seen in c programs

#include <iomanip>

io represents input and output, and manip is the abbreviation of manipulator (On c, it is only valid by inputting the abbreviation. )

##Function (Recommended learning: C language video tutorial)

Mainly for some manipulation operators such as cin and cout, such as setfill, setw, setbase, setprecision, etc. It is an I/O flow control header file, just like the formatted output in C.

The following are some common control functions:

dec sets the base to 10, which is equivalent to "%d"

hex sets the base is 16, which is equivalent to "%X"

oct. Set the base to 8, which is equivalent to "%o"

setfill( 'c' ). Set the fill character to c

setprecision( n ) Assume that the displayed valid digits are n digits

setw( n ) and the field width is n characters

The meaning of this control character is to ensure that the output width is n. For example:

cout << setw( 3 ) << 1 << setw( 3 ) << 10 << setw( 3 ) << 100 << endl;

The output result is:

_ _1_10100

(the default is right alignment). When the output length is greater than 3 (<<1000), setw(3) does not work.

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