Take a look at the snippet and choose the true statement: nums = [1, 2, 3] vals = nums del vals[:]

The correct answer is C. nums and vals have the same length. Option C is correct because vals = nums does not create a new list - it makes vals a second reference pointing to the exact same list object in memory. When del vals[:] is executed, it clears all elements from that shared list in-place, leaving both nums and vals as empty lists…

Question

Take a look at the snippet and choose the true statement:
nums = [1, 2, 3]
vals = nums
del vals[:]

Options

Avals is longer than nums
Bnums is longer than vals
Cnums and vals have the same length
DThe snippet will cause a runtime error.

How the community answered

(50 responses)

A
4% (2)
B
16% (8)
C
72% (36)
D
8% (4)

Explanation

Option C is correct because vals = nums does not create a new list - it makes vals a second reference pointing to the exact same list object in memory. When del vals[:] is executed, it clears all elements from that shared list in-place, leaving both nums and vals as empty lists with length 0.

A and B are wrong for the same reason: since there is only one list object, the two variables can never have different lengths - they are always identical.
D is wrong because del vals[:] is perfectly valid Python; slice deletion is a built-in operation that empties a list without raising any error.

Memory tip: In Python, = with a list copies the reference, not the data. Think of nums and vals as two name-tags stuck on one box - removing items from the box affects both tags. To get an independent copy, use vals = nums[:] or vals = nums.copy().

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