Format Specifiers in C

1. What are Format Specifiers?

A format specifier tells the compiler what type of data you want to print using the printf() function.
They act like placeholders inside the double quotes ” ” — and are replaced by the variable’s value during output.

Syntax:

printf(“Text %format_specifier”, variableName);

Example:

int myNum = 15;

printf(“%d”, myNum);   // Outputs: 15

2. Common Format Specifiers

3. Example – Printing Different Types

#include <stdio.h>

int main() {

  int myNum = 15;          // Integer

  float myFloat = 5.99;    // Floating number

  char myLetter = ‘D’;     // Character

  printf(“%d\n”, myNum);

  printf(“%f\n”, myFloat);

  printf(“%c\n”, myLetter);

  return 0;

}

✅ Output:

15

5.990000

D

4. Combine Text and Variables

You can combine normal text with variable values using commas ,:

Example:

int myNum = 15;

printf(“My favorite number is: %d”, myNum);

✅ Output:

My favorite number is: 15

5. Print Multiple Variables Together

You can print different types of data in one line by using multiple format specifiers:

Example:

int myNum = 15;

char myLetter = ‘D’;

printf(“My number is %d and my letter is %c”, myNum, myLetter);

✅ Output:

My number is 15 and my letter is D

6. Printing Values Without Variables

You can also print direct values (not stored in variables):

Example:

printf(“My favorite number is: %d”, 15);

printf(“My favorite letter is: %c”, ‘D’);

✅ Output:

My favorite number is: 15My favorite letter is: D

(Tip: Add \n for a new line if needed)

7. Formatting Float Values

You can control how many decimal places are shown with %.nf (where n = number of decimals).

Example:

float myFloat = 5.99;

printf(“%.2f”, myFloat);  // Outputs 5.99

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