This question belongs to Swift Programming Language , specifically the objective on variable scope and shadowing .
The code first declares:
let even = 2
This creates a constant named even in the outer scope with the value 2.
Inside the for loop, the code declares another constant with the same name:
let even = num * 2
This inner even exists only inside the loop body. It shadows the outer even, which means that within the loop, the name even refers to the loop’s local constant, not the original one. However, that inner constant goes out of scope at the end of each loop iteration.
After the loop finishes, the inner even no longer exists. So when the final line runs:
print(even)
Swift uses the original outer constant, which is still 2.
So the output is:
2
This question tests two important Swift concepts:
Scope : where a variable or constant can be accessed
Shadowing : when a local declaration temporarily hides another declaration with the same name
Therefore, the correct answer is 2 .
