This document discusses formatted and unformatted input/output functions in C programming. Formatted functions like printf() and scanf() convert data to ASCII characters for output or expect formatted input. Unformatted functions transfer raw binary data directly. Common formatted functions are printf(), scanf(), while unformatted include getch(), putchar(). Format specifiers in formatted functions determine input/output format, and data type modifiers change variable storage size.

1. Formatted Input/Output
-SHOVAKHAR BHANDARI

2. These are the functions to receive input from
keyboard and write output to VDU.
◦ These are divided into two catogories:
Formatted functions.
-Formatted output converts the internal binary
representation of the data to ASCII characters
which are written to the output file.
-printf() and scanf() are examples for
formatted input and output function.
Unformatted functions.
-Unformatted input/output transfers the internal
binary representation of the data directly between
memory and the file.
- getch(), getche(), getchar(),
gets(), puts(), putchar() etc. are
examples of unformatted input output
functions
CONSOLE I/O

3. Formatted output:
The function printf() is used for formatted output to standard output based on a format
specification.
Syntax:
printf (format_string, list_of_expressions);
where:
•format_string is the layout of what's being printed
•list_of_expressions is a comma-separated list of variables or expressions yielding results to be
inserted into the output
Formatted input:
•To read data in from standard input (keyboard), we call the scanf function. The basic form of a
call to scanf is:
• scanf(format_string, list_of_variable_addresses);

4. The Format specifier is a string used in the formatted input and output functions.
The format string determines the format of the input and output.
 The format string always
starts with a '%' character.
Example:
In the given example :
Scanf and printf are formatted
functions and “%d” “%f” are
Format specifier.
FORMAT SPECIFIER
#include<stdio.h>
int main(){
int a;
float b;
printf("Enter the value of a and b");
scanf("%d %f",&a,&b);
printf("THe value of a and b are %d and %f
respectively",a,b);
return 0; }

5. FORMAT SPECIFIER

6. DATA TYPE MODIFIERS
The prefix used in data-type to modify (either increase or decrease) the amount of storage
space allocated to a variable are data type modifiers.
For example, storage space for int data type is 4 byte for 32 bit processor. We can
increase the range by using long int which is 8 byte. We can decrease the range by using
short int which is 2 byte.
1. Long-used to store very large number.
2. Short- limits user to store small integer values from -32768 to 32767.
3. Signed-user can store both negative and positive values.
4. Unsigned - store only positive values.

7. RELATED QUESTIONS
1. What are formatted I/O functions?
2. Differentiate between formatted and unformatted functions.
3. What is the difference between Character, Integer, Float and Double data types.

8. REFRENCES
1. Let us c 14th edition.
2. https://www.c-sharpcorner.com/UploadFile/a5f59f/using-formatted-io-input-
output-functions-with-example-in/