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8.4.1: Formatting Output Continued

  • Page ID
    29079
  • Formatting using Manipulators

    The second way you can alter the format parameters of a stream is through the use of special functions called manipulators that can be included in an I/O expression.
    The standard manipulators are shown below:

    1. boolalpha: The boolalpha manipulator of stream manipulators in C++ is used to turn on bool alpha flag
    2. dec: The dec manipulator of stream manipulators in C++ is used to turn on the dec flag
    3. endl: The endl manipulator of stream manipulators in C++ is used to Output a newline character.
    4. and: The and manipulator of stream manipulators in C++ is used to Flush the stream
    5. ends: The ends manipulator of stream manipulators in C++ is used to Output a null
    6. fixed: The fixed manipulator of stream manipulators in C++ is used to Turns on the fixed flag
    7. flush: The flush manipulator of stream manipulators in C++ is used to Flush a stream
    8. hex: The hex manipulator of stream manipulators in C++ is used to Turns on hex flag
    9. internal: The internal manipulator of stream manipulators in C++ is used to Turns on internal flag
    10. left: The left manipulator of stream manipulators in C++ is used to Turns on the left flag
    11. noboolalpha: The noboolalpha manipulator of stream manipulators in C++ is used to Turns off bool alpha flag
    12. noshowbase: The noshowbase manipulator of stream manipulators in C++ is used to Turns off showcase flag
    13. noshowpoint: The noshowpoint manipulator of stream manipulators in C++ is used to Turns off show point flag
    14. noshowpos: The noshowpos manipulator of stream manipulators in C++ is used to Turns off showpos flag
    15. noskipws: The noskipws manipulator of stream manipulators in C++ is used to Turns off skipws flag
    16. nounitbuf: The nounitbuf manipulator of stream manipulators in C++ is used to Turns off the unit buff flag
    17. nouppercase: The nouppercase manipulator of stream manipulators in C++ is used to Turns off the uppercase flag
    18. oct: The oct manipulator of stream manipulators in C++ is used to Turns on oct flag
    19. resetiosflags(fmtflags f): The resetiosflags manipulator of stream manipulators in C++ is used to Turns off the flag specified in f
    20. right: The right manipulator of stream manipulators in C++ is used to Turns on the right flag
    21. scientific: The scientific manipulator of stream manipulators in C++ is used to Turns on scientific flag
    22. setbase(int base): The setbase manipulator of stream manipulators in C++ is used to Set the number base to base
    23. setfill(int ch): The setfill manipulator of stream manipulators in C++ is used to Set the fill character to ch
    24. setiosflags(fmtflags f): The setiosflags manipulator of stream manipulators in C++ is used to Turns on the flag specified in f
    25. setprecision(int p): The setprecision manipulator of stream manipulators in C++ is used to Set the number of digits of precision
    26. setw(int w): The setw manipulator of stream manipulators in C++ is used to Set the field width to w
    27. showbase: The showbase manipulator of stream manipulators in C++ is used to Turns on showbase flag
    28. showpoint: The showpoint manipulator of stream manipulators in C++ is used to Turns on show point flag
    29. showpos: The showpos manipulator of stream manipulators in C++ is used to Turns on showpos flag
    30. skipws: The skipws manipulator of stream manipulators in C++ is used to Turns on skipws flag
    31. unitbuf: The unitbuf manipulator of stream manipulators in C++ is used to turn on unitbuf flag
    32. uppercase: The uppercase manipulator of stream manipulators in C++ is used to turn on the uppercase flag
    33. ws: The ws manipulator of stream manipulators in C++ is used to skip leading white space

    To access manipulators that take parameters (such as setw( )), you must include “iomanip” header file in your program.

    #include <iomanip> 
    #include <iostream> 
    using namespace std; 
    
    int main() 
    { 
    	// performs same as setf( ) - adds the = sign to the output
    	cout << setiosflags(ios::showpos); 
    	cout << 123 << endl; 
    	
    	// This takes the value 100 and turns it into a hex value (which is 64) 
    	cout << hex << 100 << endl; 
    	
    	// Set the field width to 10 using setw()
    	cout << setfill('*') << setw(10) << 2343.0 << endl; 
    
    	return 0; 
    }

    Adapted from:
    "Formatted I/O in C++" by Somil SinghGeeks for Geeks is licensed under CC BY-SA 4.0