1: Understanding Standard Input and Output

In this lesson, we’ll delve into using standard input and output functions for reading and displaying data in C.

• Standard Input Functions:

  • scanf(): Used to read input from the standard input (keyboard).
     

    int age;
printf("Enter your age: ");
scanf("%d", &age); // Read an integer input


• Standard Output Functions:

  • printf(): Used to display output to the standard output (console).
     

    int num = 10;
printf("The number is: %dn", num); // Display an integer


2: Reading and Displaying Different Data Types

• Reading Different Data Types:

  • Use appropriate format specifiers with scanf() to read different data types.
     

    int num;
    float price;
    char initial;

    printf("Enter an integer: ");
    scanf("%d", &num);

    printf("Enter a float: ");
    scanf("%f", &price);

    printf("Enter a character: ");
scanf(" %c", &initial); // Note: Use a space before %c to consume any newline characters


• Displaying Different Data Types:

  • Use format specifiers with printf() to display various data types.
     

    int age = 30;
    float height = 5.9;
    char grade = 'A';

    printf("Age: %dn", age);
printf("Height: %.2f feetn", height); // Display float with 2 decimal places
printf("Grade: %cn", grade);


3: Formatting Output

• Formatting Output:

  • Use formatting options in printf() to control the appearance of output.
     

    int num = 12345;

    printf("Number: %dn", num); // Default formatting
printf("Number: %10dn", num); // Right-aligned within a field width of 10
printf("Number: %-10dn", num); // Left-aligned within a field width of 10
printf("Number: %010dn", num); // Zero-padded with a field width of 10


• Formatting Floats:

  • Control precision and width for floating-point numbers.
     

    float pi = 3.14159;

    printf("Pi: %fn", pi); // Default precision
printf("Pi: %.2fn", pi); // Display with 2 decimal places
printf("Pi: %10.2fn", pi); // Right-aligned within a field width of 10


4: Practice and Examples

• Practice Exercise:
  • Write a program that reads two integers from the user and displays their sum and product.
  • Use appropriate input and output functions with proper formatting.