GATE DA 2026 Set 1 — Question 50

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MSQ+2 / -0MediumFunctionsFunctions, File & Error HandlingProgramming, Data Structures & AlgorithmsListsData Types & Control StatementsVariables & Memory ManagementPython Syntax & I/O

Programming, Data Structures & Algorithms → Data Types & Control Statements → Functions

Last updated 5 September 2026

Question

Consider the given Python program. def outer(): x = [] def inner(val): x.append(val) return x return inner f1 = outer() f2 = outer() print(f1(10)) # Line P print(f1(20)) # Line Q print(f2(30)) # Line R print(f1(40)) # Line S Which of the following options is/are correct?

Correct answer (B) Output of Line Q is [10, 20]; (D) Output of Line S is [10, 20, 40] Solution The function outer creates a new list x each time it is called and returns the inner function, which forms a closure over x . 1. f1 = outer() : f1 has its own closure with x = [] . 2. f2 = outer() : f2 has a separate closure with a new x = [] . 3. print(f1(10)) : Appends 10 to f1's x . x becomes [10] . Output: [10] . 4. print(f1(20)) : Appends 20 to f1's x . x becomes [10, 20] . Output: [10, 20] . (Option B is correct) 5. print(f2(30)) : Appends 30 to f2's x (which was empty). x becomes [30] . Output: [30] . (Option C is incorrect) 6. print(f1(40)) : Appends 40 to f1's x . x becomes [10, 20, 40] . Output: [10, 20, 40] . (Option D is correct) Option A is incorrect because f1 and f2 have distinct x lists. Turn this into a strength. Explore AI-powered practice and doubt support with Success Tracker.

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Correct answer (B) Output of Line Q is [10, 20]; (D) Output of Line S is [10, 20, 40] Solution The function outer creates a new list x each time it is called and returns the inner function, which forms a closure over x . 1. f1 = outer() : f1 has its own closure with x = [] . 2. f2 = outer() : f2 has a separate closure with a new x = [] . 3. print(f1(10)) : Appends 10 to f1's x . x becomes [10] . Output: [10] . 4. print(f1(20)) : Appends 20 to f1's x . x becomes [10, 20] . Output: [10, 20] . (Option B is correct) 5. print(f2(30)) : Appends 30 to f2's x (which was empty). x becomes [30] . Output: [30] . (Option C is incorrect) 6. print(f1(40)) : Appends 40 to f1's x . x becomes [10, 20, 40] . Output: [10, 20, 40] . (Option D is correct) Option A is incorrect because f1 and f2 have distinct x lists.

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GATE DA 2026 Set 1 — Question 50

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