printf() - I/O Function

Tutorials

Cpp

Topic

How is "printf()" used in C++?

Explanation

printf() is an I/O function that prints the formatted data to the stdout. This function returns the total number of characters, but on failure a negative value is returned.

Syntax:

    int printf ( const char * format, ... );

The following table lists the type specifier used with printf()

Type	Description
c	Character
d or i	Signed decimal integer
e	Scientific notation using e character
E	Scientific notation using E character
f	Decimal floating point
g	Use the shorter of %e or %f
G	Use the shorter of %E or %f
o	Signed octal
s	String of characters
u	Unsigned decimal integer
x	Unsigned hexadecimal integer
X	Unsigned hexadecimal integer(capital)
p	Pointer address
%	A % followed by another % character will write % to the stream.

Example:

   #include <stdio.h>
   int main()
    {
      printf ("Characters: %c %c \n", 'b',42);
      printf ("Decimals: %d %ld\n", 187, 345);
      printf ("Preceding blanks: %7d \n", 2010);
      printf ("Preceding zeros: %07d \n", 2010);
      printf ("Float values : %3.2f %+.0e %E \n", 
              4.316, 4.2456, 6.1317);
      printf ("%s \n", "Hscripts");
      return 0;
}

Result:setbufeg.txt

    Characters: b
    Decimals: 1
    Preceding blanks:    2010
    Preceding zeros: 0002010
    Float values : 4.32 +4e+00 6.131700E+00
    Hscripts

In the above example the "printf()" is used with different type specifiers.