How to print % using printf()?

Asked by Tanuj

Here is the standard prototype of printf function in C.

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

The format string is composed of zero or more directives: ordinary characters (not %), which are copied unchanged to the output stream; and conversion specifications, each of argument (and it is an error if insufficiently many arguments are given).

The character % is followed by one of the following characters.

The flag character
The field width
The precision
The length modifier
The conversion specifier:

See http://swoolley.org/man.cgi/3/printf for details of all the above characters. The main thing to note in the standard is the below line about conversion specifier.

A `%' is written. No argument is converted. The complete conversion specification is`%%'.

So we can print “%” using “%%”

/* Program to print %*/
#include<stdio.h>
/* Program to print %*/
int main()
{
   printf("%%");
   getchar();
   return 0;
}

We can also print “%” using below.

   printf("%c", '%');
   printf("%s", "%");