The scanf() function reads formatted input from the standard input stream. This example reads an integer entered by the user and stores it in a variable.

#include <stdio.h>

int main()
{
    int number;

    printf("Enter a number: ");
    scanf("%d", &number);

    printf("You entered: %d\n", number);

    return 0;
}

Example Output #

Enter a number: 25
You entered: 25

Explanation #

The variable is declared before reading the input:

int number;

The scanf() call reads an integer using the %d conversion specifier:

scanf("%d", &number);

&number supplies the address of number, allowing scanf() to store the input value in that variable.

The value is then displayed using printf():

printf("You entered: %d\n", number);

The format specifier used by scanf() must correspond to the type of the object receiving the input.

Common scanf() Format Specifiers #

For scanf(), the address of the destination object is generally supplied using &. String arrays are an important exception because an array expression is converted to a pointer to its first element.