Input and Output in C

C 171 views Dec 22, 2025 1 min read

Input and Output (I/O) operations in C are used to accept data from the user and display output to the screen.
C provides standard I/O functions through the stdio.h header file.

Standard Input and Output Functions

Output Function

printf() – Displays output on the screen

Input Function

scanf() – Reads input from the user

printf() Function

Used to display output.

Syntax

printf("format string", variables);

Example

printf("Hello World");
printf("Age = %d", age);

scanf() Function

Used to take input from the user.

Syntax

scanf("format string", &variable);

Example

scanf("%d", &age);

Format Specifiers

Specifier	Meaning
`%d`	Integer
`%f`	Float
`%lf`	Double
`%c`	Character
`%s`	String

Example Program (Input and Output)

#include 

int main() {
    int age;
    float salary;

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

    printf("Enter salary: ");
    scanf("%f", &salary);

    printf("Age = %d\nSalary = %.2f", age, salary);
    return 0;
}