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C printf and scanf functions:
- printf() and scanf() functions are inbuilt library functions in C programming language 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 in C language.
- We have to include “stdio.h” file as shown in below C program to make use of these printf() and scanf() library functions in C language.
1. printf() function in C language:
- In C programming language, 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 must be in lower case.
Example program for C printf() function:
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#include <stdio.h> int main() { char ch = 'A'; char str[20] = "fresh2refresh.com"; float flt = 10.234; int no = 150; double dbl = 20.123456; printf("Character is %c \n", ch); printf("String is %s \n" , str); printf("Float value is %f \n", flt); printf("Integer value is %d\n" , no); printf("Double value is %lf \n", dbl); printf("Octal value is %o \n", no); printf("Hexadecimal value is %x \n", no); return 0; } |
Output:
Character is A
String is fresh2refresh.com Float value is 10.234000 Integer value is 150 Double value is 20.123456 Octal value is 226 Hexadecimal value is 96 |
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.
2. scanf function in C language:
- In C programming language, 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 C printf and scanf functions in C programming language:
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#include <stdio.h> int main() { char ch; char str[100]; printf("Enter any character \n"); scanf("%c", &ch); printf("Entered character is %c \n", ch); printf("Enter any string ( upto 100 character ) \n"); scanf("%s", &str); printf("Entered string is %s \n", str); } |
Output :
Enter any character
a Entered character is a Enter any string ( upto 100 character ) hai Entered string is hai |
- 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.
- It is just like in a pointer which is used to point to the variable. For more information about how pointer works, please click here.
KEY POINTS TO REMEMBER IN C PRINTF() AND SCANF():
- printf() is used to display the output and scanf() is used to read the inputs.
- printf() and scanf() functions are declared in “stdio.h” header file in C library.
- All syntax in C language including printf() and scanf() functions are case sensitive.