In C programming, printf() and scanf() are essential functions used for output and input operations. Both functions are defined in the stdio.h header file and are fundamental for interacting with the console.
The printf() function is used to print output to the console. It formats and displays data based on the specified format string.
printf("format string", argument_list);
• format string: A string that specifies how to format the output. It can include placeholders (format specifiers) for variables.
• argument_list: A list of variables or values that replace the placeholders in the format string.
• %d or %i: Integer
• %c: Character
• %s: String
• %f: Floating-point number
#include <stdio.h>
int main() {
int age = 25;
float height = 5.9;
printf("Age: %d\n", age); // Output: Age: 25
printf("Height: %.1f\n", height); // Output: Height: 5.9
return 0;
}
The scanf() function is used to read input from the console. It reads the input data based on the specified format string and stores it in the provided variables.
scanf("format string", &variable_list);
• format string: A string that specifies the format for reading input. It should match the expected type of the input.
• variable_list: A list of pointers to variables where the input data will be stored.
• %d or %i: Integer
• %c: Character
• %s: String
• %f Floating-point number
#include <stdio.h>
int main() {
int age;
float height;
printf("Enter your age: ");
scanf("%d", &age); // Reads an integer from the user
printf("Enter your height: ");
scanf("%f", &height); // Reads a floating-point number from the user
printf("Age: %d\n", age);
printf("Height: %.1f\n", height);
return 0;
}
• printf(): Used for output; formats and displays data.
• scanf(): Used for input; reads data from the user and stores it in variables.
• Ensure that the format specifiers in printf() and scanf() match the data types of the variables you are working with.
• Always use the address-of operator (&) with scanf() when reading values into variables.