C Printf

How C Printf Works

• %d - Integer
• %f - Floating-point number
• %c - Character
• %s - String

Syntax of C Printf Function

Utilising C Printf Format Specifiers

Common C Printf Format Specifiers

• %u - Unsigned integer
• %ld - Long integer
• %lu - Unsigned long integer
• %lld - Long long integer
• %llu - Unsigned long long integer
• %x - Lowercase hexadecimal integer
• %X - Uppercase hexadecimal integer
• %o - Octal integer
• %e - Scientific notation (lowercase)
• %E - Scientific notation (uppercase)
• %g - Shortest representation of %f and %e
• %G - Shortest representation of %f and %E
• %% - Print a single percent sign '%'

Advanced C Printf Format Specifiers

Exploring C Printf Examples

Basic Printf Examples

int number = 42;
printf("The answer is: %d", number);

float pi = 3.14159;
printf("The value of pi is approximately: %f", pi);

char letter = 'A';
printf("The first letter of the alphabet is: %c", letter);

char name[] = "Alice";
printf("Hello, %s!", name);

Complex Printf Examples

printf("%-10s%10s%10s\n", "Name", "Age", "Height");
printf("%-10s%10d%10.2f\n", "Alice", 25, 1.68);
printf("%-10s%10d%10.2f\n", "Bob", 30, 1.82);

Name          Age    Height
Alice          25      1.68
Bob            30      1.82

int number = 255;
printf("Decimal: %d, Hexadecimal: %x, Octal: %o", number, number, number);

double large_number = 123456789.987654;
printf("Default format: %g \n", large_number);
printf("Scientific notation: %.3e \n", large_number);
printf("Fixed notation with precision: %.4f \n", large_number);

Default format: 1.23457e+08 
Scientific notation: 1.235e+08 
Fixed notation with precision: 123456789.9877 

Working with C Printf Double

Printing Double Values Using C Printf

double value = 3.14159265359;
printf("Double value: %lf\n", value);

Double value: 3.141593

Format Specifiers for C Printf Double

Implementing C Printf Arguments

In C programming, the Printf function is extensively used to display outputs, such as variables and text. By implementing variable arguments and using modifiers in C Printf, you can handle a varying number of arguments with precision and in a more efficient manner.

Utilising Variable Arguments in C Printf

#include 

void my_printf(const char *format, ...);

va_list args;

va_start(args, format);

int number = va_arg(args, int);

va_end(args);

#include 
#include 

void my_printf(const char *format, ...);

int main() {
  my_printf("I am %d years old and I live in %s\n", 25, "London");
  return 0;
}

void my_printf(const char *format, ...) {
  va_list args;
  va_start(args, format);

  while (*format != '\0') {
    if (*format == '%') {
      format++;
      switch (*format) {
        case 'd': {
          int number = va_arg(args, int);
          printf("%d", number);
          break;
        }
        case 's': {
          char *string = va_arg(args, char *);
          printf("%s", string);
          break;
        }
      }
    } else {
      putchar(*format);
    }
    format++;
  }

  va_end(args);
}

Using Modifiers with C Printf Arguments

printf("%5d", 15); // Output: "   15"

printf("%.3f", 3.14159); // Output: "3.142"

printf("%-5d", 15); // Output: "15   "

Different C Printf Types

Standard Output Types in C Printf

• %d or %i - Signed integer
• %u - Unsigned integer
• %f - Floating-point number
• %lf - Double floating-point number
• %c - Character
• %s - String
• %x or %X - Lowercase or uppercase hexadecimal integer
• %o - Octal integer
• %e or %E - Lowercase or uppercase scientific notation
• %g or %G - Lowercase or uppercase shortest representation of %f and %e
• %p - Pointer address
• %% - Literal percentage character

Custom Output Types in C Printf

// Set a minimum width of 5 characters for integer value
printf("%5d", 42); // Output: "   42"

// Display a floating-point number with 3 decimal places
printf("%.3f", 3.14159); // Output: "3.142"

// Display a left-aligned integer value with a minimum width of 5 characters
printf("%-5d", 42); // Output: "42   "

// Display an integer value with leading zeros and a minimum width of 5 characters
printf("%05d", 42); // Output: "00042"