Python Coding Challange - Question with Answer (01010725)

 

Step-by-Step Explanation:

1. x = [1, 2, 3]

   • A list x is created.

   • Lists are mutable in Python.

2. modify(x)

   • You pass the list x to the function modify.

   • The parameter a now refers to the same list as x (initially).

3. Inside the function:

   • a = a + [4, 5]

     • This creates a new list by combining a and [4, 5].

     • The result [1, 2, 3, 4, 5] is assigned to a, but this does not affect the original list x.

     • a now refers to a new list, but x still points to the original [1, 2, 3].

4. After the function call:

   • x is unchanged.

   • So print(x) outputs:

   
   [1, 2, 3]

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 Why didn't the original list change?

Because this line:

a = a + [4, 5]

does not modify the list in-place. It creates a new list and reassigns it to a, breaking the reference to the original list x.

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✅ To modify the original list, you'd use:

def modify(a):
    a += [4, 5]

Or:

def modify(a):
    a.append(4) 
    a.append(5)

These modify the list in-place, so x would then change to [1, 2, 3, 4, 5].

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