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Outputs

This section focuses on the printf() function for displaying output in C programming.

printf() Function

The printf() function is used to display text, numbers, or other data on the console. It is part of the standard input/output library (stdio.h), which must be included at the top of your program:

#include <stdio.h>

Basic Syntax

printf("format string", arguments);
  • Format string: The text to display, which may include placeholders (format specifiers) for variables.
  • Arguments: The values or variables to be inserted into the format string.

Example: Basic Output

#include <stdio.h>

int main() {
    printf("Hello, World!\n");
    return 0;
}

Output:

Hello, World!

Explanation:

  • "Hello, World!" is the text to print.
  • \n adds a new line after the text.

Printing Variables

printf() can display variable values using format specifiers (covered previously).

Example: Printing Variables

#include <stdio.h>

int main() {
    int age = 25;
    printf("Age: %d\n", age);
    return 0;
}

Output:

Age: 25

Common Mistakes

  • Forgetting \n: Without it, the next output may appear on the same line.
  • Missing stdio.h: Always include #include <stdio.h> for printf() to work.
  • Mismatched Arguments: Ensure the number of format specifiers matches the arguments.

Example: Incorrect vs. Correct

#include <stdio.h>

int main() {
    int num = 42;
    // Incorrect: Missing argument
    printf("Number: %d\n");
    // Correct
    printf("Number: %d\n", num);
    return 0;
}

Output:

Number: (undefined behavior)
Number: 42

Summary

  • Use printf() to display text and variables in C.
  • Include escape sequences like \n and \t for formatting.
  • Ensure #include <stdio.h> is present and arguments match format specifiers.