C How user-defined function works?

User-Defined Function in C

In C, a user-defined function is a function created by the programmer to perform a specific task. Here are the steps for how a user-defined function works:

  1. Function Declaration and Definition:
  2. The user declares and defines the function using the following syntax: c return_type function_name(parameter_list) { // function body }
  3. The return_type specifies the data type of the value the function returns.

  4. The function_name is the name of the function, and the parameter_list contains the input parameters for the function [3].

  5. Function Call:

  6. To use the user-defined function, the programmer calls it within the main program or another function using the function_name followed by parentheses containing any required arguments.
  7. The function call transfers control to the function, and the statements within the function are executed.

  8. After the function completes its task, it returns control to the calling function or the main program.

  9. Function Parameters and Arguments:

  10. The function may have parameters, which are variables used to pass values into the function.
  11. When the function is called, the values passed to the function are called arguments.

  12. These arguments are used within the function to perform the desired operations.

  13. Return Statement:

  14. Inside the function, the return statement is used to return a value to the calling function or the main program.

  15. If the function does not return a value, the return statement is optional, and the function simply executes the statements within its body and then returns control to the calling function or the main program [3].

  16. Example:

  17. Here's an example of a simple user-defined function in C that calculates the square of a number: ```c #include

    int square(int num) { return num * num; }

    int main() { int result = square(5); printf("The square of 5 is %d", result); return 0; } `` - In this example, thesquarefunction takes an integer as an argument, calculates its square, and returns the result. Themainfunction then calls thesquare` function and prints the result.

These are the fundamental steps involved in the creation, usage, and execution of a user-defined function in the C programming language.