C Sharp (C#) - Collections
Given a List<int> named
numbers containing {1, 2, 3, 4, 5}, which code snippet correctly doubles each number in the list?Given a List<int> named numbers containing {1, 2, 3, 4, 5}, which code snippet correctly doubles each number in the list?
hard🚀 Application Q15 of 15
Step-by-Step Solution
Solution:
Step 1: Understand how to modify List elements
Using a for loop with index allows modifying elements directly by assignment.Step 2: Evaluate each option's effect
for (int i = 0; i < numbers.Count; i++) { numbers[i] = numbers[i] * 2; } modifies elements in place. foreach (int n in numbers) { n = n * 2; } modifies copy of elements (no effect). numbers = numbers.Select(n => n * 2).ToList(); creates a new list but requires LINQ and ToList(). numbers.ForEach(n => n = n * 2); modifies copies in ForEach (no effect).Final Answer:
for (int i = 0; i < numbers.Count; i++) { numbers[i] = numbers[i] * 2; } -> Option BQuick Check:
Use for loop with index to update List elements [OK]
Quick Trick: Use for loop with index to update List items directly [OK]
Common Mistakes:
MISTAKES- Using foreach expecting to modify list items
- Using ForEach with lambda that doesn't assign back
- Not creating new list when using LINQ Select
Master "Collections" in C Sharp (C#)
Want More Practice?
15+ quiz questions · All difficulty levels · Free
Free Signup - Practice All QuestionsMore C Sharp (C#) Quizzes