Can any one explain why the result is 15 and not 9 ?

Question

def func(level):
if level==1:
return 1
else:
return level + func(level-1)

print(func(5))

Answer 1

When level reaches 1 the if statement is true:

if level == 1
return 1

So, we are no longer calling the function over again when level equals to 1.

This is what it would look like going through this step by step:

First call the function:
func(5)

Now:
is level == 1 true? No, level equals 5.
return level + func(level-1)
Is equivalent to:
return 5 + func(4)

What is func(4) equal to?
is level == 1 true? No, level equals 4.
return level + func(level-1)
is equivalent to:
return 4 + func(3)

What is func(3) equal to?
is level == 1 true? No level equals to 3.
return level + func(level-1)
Is equivalent to:
return 3 + func(2)

What is func(2) equal to?
is level == 1 true? No level equals 2.
return level + func(level-1)
Is equivlent to:
return 2 + func(1)

What is func(1) equal to?
is level == 1 true? Yes!
return 1

Now, func(1) = 1.
So, func(2) = 2 + func(1) = 2 + 1 = 3
So, func(3) = 3 + func(2) = 3 + 3 = 6
So, func(4) = 4 + func(3) = 4 + 6 = 10
So, func(5) = 5 + func(4) = 5 + 10 = 15
Final answer: 15

Answer 2

5 + 4 + 3 + 2 + 1 = 15

Answer 3

why did the program done a loop without any loop tools as while and for ???
why the answer is not only 5+4 = 9
can you please explain

Answer 4

thanks alot