You might want to assign the same function with 3 different parameters to 3 different variables as below: The answer to that is simple, you might not want your results to disappear and you might to assign your results to variables and use them elsewhere in your program. You might think, why do I need to return a value? Why can’t I just print the result and be done? But it will return None object due to lack of return statement. Normally, you might expect my_result to equal 4. When you try to assign it to a variable it won’t return any value. Often times, you want your function to do more than just printing on the display for the user, if you’re not using the return command your function will run and end, but it will not be equal to any value.Ībove function might print the value you intended to the display. Unless you use return in your function it will not return any value.

To call other functions from inside a function.

In libraries to create class structures which can consist of multiple functions.

In development environment to tidy up the code and make it more readable and more accessible.

In programming languages (such as Python, Rust, Go, JavaScript, R etc.) to create built-in functions from most repetitive and anticipated programming language tasks.

In GUI applications to execute specific user interface inputs such as pressing a button, cursor click, pinching, swapping etc.

In finance to create custom functions which execute specific tasks.

In data science to eliminate repetitive tasks.

In programming functions are used everywhere. By defining your own functions, you can automate a similar task instead of typing the whole function again and again.Īfter you define your function you can just call its name and execute it over and over for different applications and parameters. Coders usually have a practical mindset and don’t like to repeat similar tasks.

Python function exercises