Python Coding Challenge - Question with Answer (ID -051225)

 

1. What reduce() Does

reduce() combines all elements of a list into a single value using a function.

Example logic:

reduce(lambda x, y: x + y, [1, 2, 3])
# works like this:
# 1 + 2 = 3
# 3 + 3 = 6

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🔹 2. Your List Has Only ONE Element

a = [5]

Since the list has only one element, there is:

• ❌ No second value to add

• ✅ So reduce() simply returns the same single value

So:

reduce(lambda x, y: x + y, [5]) → 5

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🔹 3. The Loop Runs 3 Times

for i in range(3):

This runs for:

• i = 0

• i = 1

• i = 2
  👉 Total = 3 times

Each time, this runs:

print(reduce(lambda x, y: x + y, a))

And each time it prints:

5

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✅ Final Output:

5
5
5

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 Key Trick in This Code

• reduce() with a single-element list always returns that element

• The loop just repeats the same result

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