Chapter 5 - Functions & Recursion

 

Functions and recursion are important concepts in the C programming language.

Function In C

A function is a block of code that performs a specific task and returns a value or result. Functions allow you to organize and reuse your code, making it more readable and maintainable. Functions are declared with the keyword "void" or a data type. Functions can also take in parameters, which are used to pass values into the function.

Recursion In C

Recursion is a technique in which a function calls itself. This allows for the function to perform a repetitive task in a more efficient and elegant way. In order to use recursion, a function must have a base case and a recursive case. The base case is the condition in which the function stops calling itself, and the recursive case is the condition in which the function calls itself again with a modified set of parameters.

Here is an example of a simple function in C:

int add(int a, int b) {
  return a + b;
}

This function takes in two integers, "a" and "b", and returns the sum of the two numbers.

Here is an example of a simple recursive function in C:

int factorial(int n) {
  if (n == 0) {
    return 1;
  }
  else {
    return n * factorial(n-1);
  }
}

This function takes in an integer, "n", and returns the factorial of that number. The base case is when "n" is 0, in which case the function returns 1. The recursive case is when "n" is greater than 0, in which case the function calls itself with the parameter "n-1". This process continues until the base case is reached.

In conclusion, functions and recursion are powerful tools in the C programming language that allow you to organize and reuse your code, making it more readable and maintainable. Understanding and mastering these concepts is essential for any programmer working in C.