C printf()

Formatted Output and the printf() function

One of the common task in every program is the printing of output. We use the output to request input from a user and later display the status/result, computations etc. In C programming there are several functions for printing formatted output.

The printf() function is used to format and print a series of characters and values to the standard output.

Syntax:

int printf(const char *format-string, argument-list);

Parameters:

Format strings specify notation, alignment, significant digits, field width, and other aspects of output formats. It can contain ordinary alphanumeric characters; along with escape characters, conversion specifiers, and other characters. Format specifications are made up of a the percent sign (%) followed by one of the following conversion operators, which determine what printf does with its arguments.

Conversion Specifiers:

Return value

• Returns the number of bytes printed.

Examples: printf() function

To use the printf() function we must include the stdio library in the source code. To do this just place the following code at the beginning of your program.

#include <stdio.h>

To print a simple message in computer screen you might call printf() function as follows:

#include <stdio.h>
main()
{
printf ("You are learning printf() function");
}

Output:

You are learning printf() function

In the above examples, the cursor will remain at the end of the printed output. If you repeat the above code in the following way the second message would appear immediately after the first one.

#include <stdio.h>
main()
{
printf("You are learning printf() function");
printf("You are learning printf() function");
}

Output:

You are learning printf() function You are learning printf() function

Escape sequences in C

You will get an idea of using the escape sequences from the following example.

#include<stdio.h>
main()
{
printf("Create a new line\n");
printf("Print a double quotes (\") within a string\n");
printf("Print a single quotes (\') within a string\n");
printf("Print a Backslash\\ within a string\n");
printf("Using Backspace\b within a string\n");
printf("Using\tTab within a string\n");
}

Output:

Create a new line
  Print a double quotes (") within a string
  Print a single quotes (') within a string
  Print a Backslash\ within a string
  Using Backspace within a string
  Using     Tab within a string

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