Function

Question

words = ["hello", "world", "spam", "eggs"]
counter = 0
max_index = len(words) - 1

while counter <= max_index:
word = words[counter]
print(word + "!")
counter = counter + 1

what is the function of '-1' in the above block of code?

Answer 1

Indexes begin at 0, so the max index is always one less than the length of the array.

Answer 2

This is a important future in arrays - not only in Python.
Because, len function returns number of items in array. But these are indexed from 0 to number-1.
In this example, number of items in array is 4. But are indexed from 0 to 3. So, this is the reason, for substract 1 from number to get the max_index

Answer 3

Thanks Petr and Zen