Either through user-defined header filesВ or by adding a function block directly to the program. User-defined functions can be added to the program in two ways. All the user-defined functions need to be called(directly or indirectly) inside the main() function in order to be executed. A program can have more than one user-defined functions. The user can program it to perform any desired function.It is like customizing the functions that we need in a program. User-defined functions are the ones created by the user.

log() finds the logarithmic value of the number.ДЄpart from and there are many other header files that contain library functions such as that contains clrscr() and getch().

sqrt() finds the square root of the number.

cos() finds the cosine of the given number.

exp() finds the exponent of the given number.

sin() finds the sine of the given number.

pow() finds the power of the given number.

The library function В includes these common functions(there are many other functions too):

getchar() takes character input from the user.

scanf() used to take the userвЂ™s input which can be a character, numeric value, string,etc.

printf() shows the output in the userвЂ™s format.

The library function includes these common functions(there are many other functions too):

To use these functions we need to import the specific header files. These functions are defined in the header file. They are used for String handling, I/O operations, etc. There functions are already defined in the C compilers. C Programming Language has two types of functions: Types of FunctionsДЄpart from the functions that programmers create according to their requirement, C compilers has some built-in functions that can be used anytime by the programmer. LetвЂ™s learn more about these functions: 2. With so many advantages, functions are a boon for any programmer.

A function can be used to create our own header file which can be used in any number of programs i.e.

Another advantage here is that functions can be individually tested which is more convenient than the above mentioned process.

In case we need to test only a particular part of the program we will have to run the whole program and figure out the errors which can be quite a complex process.

It reduces the complexity of a program and gives it a modular structure.

The control will always come back to the main() function.

The C compiler follows top-to-down execution, so the control flow can be easily managed in case of functions.

Breaking the code in smaller Functions keeps the program organized, easy to understand and makes it reusable.

Use of functions enhances the readability of a program.

Here are several advantages of using functions in your code: And after the execution of any function block, the control always comes back to the main() function. Suppose a task needs to be performed continuously on many data at different points of time, like one at the beginning of the program and one at the end of the program, so instead of writing the same piece of code twice, a person can simply write it in a function and call it twice. The compiler always executes the main() function first and then any other function(if it is called from the main method).ДЄ function is basically a block of statements that performs a particular task. The most common function that we use in our day-to-day programming is the main() function. Every C program has at least one function. The programmer divides the program into different modules or functions and accesses certain functions when needed. A function is a group of statements that are executedВ whenever the function is called to perform a specific designated task.Д¬ programming makes use of modularity to remove the complexity of a program.

How to write c code functions