Does a recursive function need a return?

4 Answers. The recursive calls of the function do not influence on the returned value. Only the first return met in the first instance of your recursive function will return a value to the parent function. Any other return met will just stop the function’s instance the program is currently in.

Does every recursive function need a return value?

All functions – recursive or not – have one or more return . The return may or may not include a value. It is for you to decide when you write the function. All explicit written return statements must return the correct type.

Why recursion is bad in Python?

When is recursion bad in Python? Recursion can be considered bad in Python when there is a more optimal way to implement the same algorithm using iteration or the recursive use case has the potential to generate more than 1000 function calls on the call stack.

What should a recursive function return?

A recursive function usually receive an argument to be processed and return a final value that bubbles(returned) up to the first caller. When you call a recursive function, you should prepare a test for an escape. Otherwise you might end up in an infinite loop.

Can return values be passed back through recursive calls?

You need to pass through the String[][] compactArray parameter and return that. This is the result of your method that will be returned at the end. Returning starts when the deepest level of recursion is done. Then everything is passed through till the first call of your method.

What happens if a recursive function never returns?

This case—when the function completes without making a recursive call—is called the base case. If a recursion never reaches a base case, it will go on making recursive calls forever and the program will never terminate.

What are the two most important elements when writing a recursive function?

Every recursive function has two components: a base case and a recursive step.

Is Python recursion slow?

Recursion is slower and it consumes more memory since it can fill up the stack. But there is a work-around called tail-call optimization which requires a little more complex code (since you need another parameter to the function to pass around) but is more efficient since it doesn’t fill the stack.

Should you use recursion Python?

Using recursion is great because it takes many of the incremental sub problems out of your hands. But when you are try to fully understand the sub problems that you are solving and how they are being solved, it might be worth implementing an iterative solution.

Can a recursive method have more than one recursive call?

A recursive implementation may have more than one base case, or more than one recursive step. For example, the Fibonacci function has two base cases, n=0 and n=1.

Does void return anything?

Void functions are created and used just like value-returning functions except they do not return a value after the function executes. In lieu of a data type, void functions use the keyword “void.” A void function performs a task, and then control returns back to the caller–but, it does not return a value.

What happens if you call a function recursively and not return it?

In the case of recursion, this immediate caller can be another invocation of that same function. In most languages, if you don’t use the return value of a function you called (recursively or not), either that return value gets discarded or it is a diagnosable error.

Is it possible to return none from a function?

No. If a return statement is not reached before the end of the function then an implicit None is returned. If a return statement is not reached, the function returns None. I’m not sure what you really are trying to do.

What happens to the return value of the last function call?

There are some languages where the return value of the last function call gets automatically re-used as the return value of the current function invocation, but they don’t differentiate between normal and recursive function calls. Assuming unused return values get silently discarded, if you had written the code like this:

What happens if you don’t return something in an IF statement?

If you don’t return something (perhaps only in one arm of an if ), then None will be returned to your caller, regardless of whether you call any other function in that branch, regardless of what that function might return if you do call something, and regardless of whether the function you call happens to be the same function you’re inside.