C Programming Lecture Notes

Introduction

• Presenter: Padma
• Topic: Standard Library Functions in C Programming

Recap from Previous Lecture

• User-defined functions were discussed.

Standard Library Functions

• Predefined functions available in C.
• Example: printf function to print text on the screen.
  • Definition is already provided by C.
  • Included from stdio.h header file.
• Input Function: scanf is also a standard library function from stdio.h.

Importance of Header Files

• Various header files in C contain different standard library functions.
• Example Header Files:
  • math.h: Contains mathematical functions.
    • Functions:
      • sqrt: Computes the square root of a number.
      • cbrt: Computes the cube root of a number.
      • pow: Computes the power of a number.

Example Usage of math.h

1. Square Root Example:

   • Include math.h
   • Declare variable num and assign value 25.
   • Print square root using printf with sqrt(num).
   • Output: 5

2. Cube Root Example:

   • Change num to 27 and use cbrt(num).
   • Output: 3

3. Power Calculation Example:

   • Declare variables a (value 5) and b (value 2).
   • Use pow(a, b) to get 5 raised to the power of 2.
   • Output: 25
   • Change b to 3 for output 125.

Other Libraries in C

• ctype.h: Provides functions for character operations.
  • Functions:
    • toupper: Converts character to uppercase.
    • tolower: Converts character to lowercase.

Benefits of Standard Library Functions

• Saves time as definitions are provided.
• Functions are tested and optimized for performance.
• Constantly updated by developers.

Programming Task

• Create a program that computes the result of a number raised to the power of its square root.
  • Steps:
    1. Take input from user.
    2. Compute square root using sqrt function.
    3. Compute power using pow function.
    4. Print the result.
• Reference materials available on GitHub.

Conclusion

• Engage with the video by liking, commenting, and subscribing.
• Upcoming quiz on the correct way to include library functions.

Resources

• Links to resources and further readings provided in the video description.