 Hello friends, I am Sanjay Gupta. I welcome you on my YouTube channel. You can watch various programming related videos here. My channel contains more than 800 videos. You can search these videos through the keyword programming by Sanjay Gupta. In this video, I am going to demonstrate you how to define multiple functions in C programming. For example, I am taking addition, subtraction, multiplication and division of two numbers. So I will be defining four functions in a single C program. So first of all, I am including a header file sddi.h. Now I am going to declare four functions. This is first function declaration. Its return type is float. Name is sum and I will be passing two arguments of float type. Similarly, second function declaration. Return type is float and two arguments of float type. Then third multiplication and fourth one is division. So these are total four function declaration. Now I am going to define main function where I will be calling these functions. Here I have declared three variables ABC of float type. Now with the help of printf scanf, I am going to read two numbers from user. First number will be stored inside A and second number will be stored inside B. After reading values, now I am going to call these functions one by one. So first I am going to call sum passing two values A and B and the result will be received inside C variable. Now I am going to print the result with the help of printf. So this way I have called sum function. Then I am going to call subtraction and again the help of printf. I am going to display the result on output screen. So this is second function call. Now I am going to call multiplication function. Result will be stored inside C. Then with the help of printf, result will be displayed on output screen and at last I am going to call division function. Here result will be stored inside C variable and that will be displayed on output screen with the help of printf. So this way I have called all four functions. So I have completed two parts of function. First one is declaration which is available before main and second one is calling which is available inside main. Now I have to define these functions. So first I am going to define sum function. So you can see definition of sum function. It is receiving two parameters in x and y. These are added into z and z is returned with the help of return keyword. So when this return keyword will be executed its value will be stored where this sum function is called. So in our example it is called at line number 13. So at line number 13 C will be receiving the value which is available inside z variable and that will be displayed on output screen with the help of line number 14. Now I am going to copy this function definition. I am pasting it. Now I am changing name of this function as sub and plus is replaced with minus. So this is second function definition. Similarly third for multiplication and fourth for division. So this way I have defined all four function definition in this program. So I hope you have understood that we can define any number of functions in a C program as per our requirement. Now I am going to execute this code so that you can understand how it is executing or how it is processing. So it is asking for two numbers. I am entering first number as 10 and second number as 5. You can see the output. Sum is 15. Subtraction is 5. Multiplication is 50 and division is 2. And all the results are displayed in form of float values because I have used data type as float. So I hope you have understood how we can define more than one functions in a C program. If you want to watch more programming related videos, you can follow my YouTube channel. You can subscribe it. Thank you for watching this video.