scanf in C
Last Updated :
06 May, 2023
In C programming language, scanf is a function that stands for Scan Formatted String. It is used to read data from stdin (standard input stream i.e. usually keyboard) and then writes the result into the given arguments.
- It accepts character, string, and numeric data from the user using standard input.
- scanf also uses format specifiers like printf.
scanf Syntax
The syntax of scanf() in C is similar to the syntax of printf().
int scanf( const char *format, ... );
Here,
- int is the return type.
- format is a string that contains the format specifiers(s).
- “…” indicates that the function accepts a variable number of arguments.
Example format specifiers recognized by scanf:
%d to accept input of integers.
%ld to accept input of long integers
%lld to accept input of long long integers
%f to accept input of real number.
%c to accept input of character types.
%s to accept input of a string.
To know more about format specifiers, refer to this article – Format Specifiers in C
Example:
int var;
scanf(“%d”, &var);
The scanf will write the value input by the user into the integer variable var.
Return Value of scanf
The scanf in C returns three types of values:
- >0: The number of values converted and assigned successfully.
- 0: No value was assigned.
- <0: Read error encountered or end-of-file(EOF) reached before any assignment was made.
Why &?
While scanning the input, scanf needs to store that input data somewhere. To store this input data, scanf needs to known the memory location of a variable. And here comes the ampersand to rescue.
- & is also called as address of the operator.
- For example, &var is the address of var.
Example of scanf
Below is the C program to implement scanf:
C
#include <stdio.h>
int main()
{
int a, b;
printf("Enter first number: ");
scanf("%d", &a);
printf("Enter second number: ");
scanf("%d", &b);
printf("A : %d \t B : %d" ,
a , b);
return 0;
}
|
Output
Enter first number: 5
Enter second number: 6
A : 5 B : 6
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