Why do we need the return statement?

what is the function? the return statement returns the value computed by the function to the point in the code where the function was called, and also stops the running of the function. some functions create a 'side-effect' and if that is the purpose a return statement may not be necessary. for example, a function that changes the color of some text might not need to return anything. a return statement by itself can be used to stop and exit the function on a certain condition, if that is desired. like in a keydown event handler, if certain keys are pressed and you want nothing to happen, you can just return and the function will exit.