What's covered
Key facts
AND, OR, NOT: Meaning
An AND gate's output is true only when both inputs are true.
Boolean Logic in Programming
IF age >= 18 AND has_ticket runs the body only when both conditions are true.
Logic Gates and Circuits
An AND gate outputs 1 only when all inputs are 1.
Truth Tables
For A=1, B=0, the value of A AND (not B) is 1 AND 1 = 1 (true).
AND, OR, NOT: Meaning
true AND (false OR true) = true AND true = true.
Boolean Logic in Programming
With x = 5, the expression (x > 0) and (x < 10) evaluates to true (both conditions hold).
Logic Gates and Circuits
A logic gate is a piece of hardware that performs a Boolean operation on its input(s).
Truth Tables
When both inputs of AND are 1, the output is 1 (true).
AND, OR, NOT: Meaning
true AND false = false.
Boolean Logic in Programming
Booleans are used in IF statements: the condition is evaluated as either true or false.
Practice questions with answers
A taste of the 36 questions in this topic, answers marked. Sign up to practise the full set with spaced repetition.
When is an AND gate's output true?
- •When at least one input is true
- ✓When both inputs are true
- •When neither input is true
- •When the inputs are different values
How are Booleans used in IF statements?
- ✓Conditions evaluate true or false
- •Functions return integer values only
- •Loops count how many times code runs
- •Variables store numbers as text strings
What is a logic gate?
- •A circuit that converts analogue signals to digital
- •A memory chip storing binary values
- ✓Hardware doing a Boolean operation
- •Software that filters network traffic
Rows in an AND truth table with two inputs?
- •Eight rows in total
- ✓Four rows in total
- •Six rows in total
- •Two rows in total
When is an OR gate's output true?
- •Only when both inputs are false
- •Only when both inputs are true
- ✓When any input is true
- •When the two inputs have opposite values
IF age >= 18 AND has_ticket: when does it run?
- ✓Only when both are true
- •When either is true (one needed)
- •When neither is true (zero needed)
- •When the age is below 18 only
Three minutes a day. Knowledge that sticks.
Practise all 36 Boolean Logic questions with spaced repetition, so what you revise today is still there in the exam. Free to use, no card needed.