What does the operation a += 5 do to the variable a?

• A. Sets a equal to 5.
• B. Increments by 5 only if a is positive.
• C. Sets a equal to a plus 5.
• D. Deletes 5 from a.

Answer: (C)

An augmented assignment adds a value to the current contents of a and stores the result back in a. Specifically, a += 5 takes whatever a is now, adds 5, and assigns that sum to a. It’s exactly the same as a = a + 5. This updates a regardless of its prior value (positive, negative, or zero) and does not set a to 5 or depend on a’s sign. For example, if a is 3, it becomes 8; if a is -2, it becomes 3. This is a common shorthand to update a variable by a fixed amount.