N5 SDD - Logical Operators Starter Plenary

What does the AND logical operator do in programming?

• The AND operator returns true if all operands are true.
• The AND operator is used to concatenate strings in programming.
• The AND operator always returns false regardless of the operands.
• The AND operator returns true if at least one operand is true.

In a logical expression, what is the result of NOT true?

• false
• null
• error

• true

Given the following code, what will be the output?

• False

• True

• TrueFalse

• True False

Answer explanation

The and operator returns True only if both operands are True. In this case:

• a is True

• b is False

Since b is False, the expression a and b evaluates to False. Therefore, the output of the code is False.

What does the OR logical operator do in programming?

• The OR operator returns true only if both operands are true.
• The OR operator is used to concatenate strings in programming.
• The OR operator performs a calculation on integers.

• The OR logical operator returns true if at least one operand is true.

What will be the output of the following code?

Answer explanation

The or operator returns True if at least one of the operands is True. In this case:

• x > 6 evaluates to False because 5 is not greater than 6.

• y < 15 evaluates to True because 10 is less than 15.

Since the or operator only requires one of the conditions to be True for the entire expression to be True, the expression (x > 6) or (y < 15) evaluates to True.

Therefore, the output of the code is True.

In a logical expression, what is the result of NOT true?

• null
• error

• false
• true

What will be the output of the following code?

• 5

• 10

• True

• False

Answer explanation

The not operator inverts the boolean value of the expression it precedes. In this case:

• x > 3 evaluates to True because 5 is greater than 3.

• Applying the not operator to True inverts it to False.

Therefore, the expression not (x > 3) evaluates to False, and the output of the code is False.

Given the following code, what will be the output?

• True

• False

• Error

• True False

Answer explanation

Here’s the step-by-step evaluation:

1. not c evaluates to not True, which is False.

2. b and not c evaluates to False and False, which is False.

4. a or (b and not c) evaluates to True or False, which is True.

Therefore, the correct answer should be True.