• printf() and scanf() functions are inbuilt library functions in C which are available in C library by default. These functions are declared and related macros are defined in “stdio.h” which is a header file.

• We have to include “stdio.h” file as shown in below C program to make use of these printf() and scanf() library functions.

 

C printf() function:

• printf() function is used to print the “character, string, float, integer, octal and hexadecimal values” onto the output screen.

• We use printf() function with %d format specifier to display the value of an integer variable.

• Similarly %c is used to display character, %f for float variable, %s for string variable, %lf for double and %x for hexadecimal variable.

• To generate a newline,we use “\n” in C printf() statement.

 

Note:

• C language is case sensitive. For example, printf() and scanf() are different from Printf() and Scanf(). All characters in printf() and scanf() functions

 

Example program for C printf() function:

 

• Output:

 

You can see the output with the same data which are placed within the double quotes of printf statement in the program except

• %d got replaced by value of an integer variable (no),

• %c got replaced by value of a character variable (ch),

• %f got replaced by value of a float variable (flt),

• %lf got replaced by value of a double variable (dbl),

• %s got replaced by value of a string variable (str),

• %o got replaced by a octal value corresponding to integer variable (no),

• %x got replaced by a hexadecimal value corresponding to integer variable

• \n got replaced by a newline

 

C scanf() function:

• scanf() function is used to read character, string, numeric data from keyboard

• Consider below example program where user enters a character. This value is assigned to the variable “ch” and then displayed.

• Then, user enters a string and this value is assigned to the variable ”str” and then displayed.

 

Example program for printf() and scanf() functions in C:

 

Output:

 

• The format specifier %d is used in scanf() statement. So that, the value entered is received as an integer and %s for string.

• Ampersand is used before variable name “ch” in scanf() statement as &ch.