Question

Consider the code segment below.

Line 1: IF (b ≠ 0) Line 2: { Line 3: a ← a/b Line 4: } Line 5: ELSE Line 6: { Line 7: a ← a*b Line 8: }
Which of the following changes will NOT affect the results when the code segment is executed?
Option 1: Changing Line 1 to "IF (b = 0)"
Option 2: Changing Line 3 to "a ← a*b"
Option 3: Changing Line 5 to "ELSE IF (b > 0)"
Option 4: Changing Line 7 to "a ← a-b

Answer 1

Option 2, changing Line 3 to "a ← a*b" would NOT affect the results, as this operation is already performed in Line 7, assuming 'b' is not 0. Other options would alter the program's logic or outcome.

Step-by-step explanation:

The code segment provided is a conditional structure that performs different mathematical operations on variable 'a' depending on the value of variable 'b'. Analyzing the given options:

1. Changing Line 1 to "IF (b = 0)" would affect the results because it would invert the condition, executing Line 3 when 'b' is 0 which would be a division by zero error, and Line 7 when 'b' is not 0.
2. Changing Line 3 to "a ← a*b" does not change the original intent of Line 3 since 'a ← a*b' is already what Line 7 does, so this change will not affect the results as long as 'b' is not 0.
3. Changing Line 5 to "ELSE IF (b > 0)" would affect the results since it introduces an additional condition for executing Line 7 which is not in the original code.
4. Changing Line 7 to "a ← a-b" would also affect the results as it changes the operation from multiplication to subtraction, which is a different mathematical operation.

From the given options, Option 2 would NOT affect the results when the code segment is executed as it does not change the existing functionality of the program provided that 'b' is not 0.
Multiplying or dividing by the same number does not alter the equality, but changing to subtraction will definitely give a different result.