Logical Operators Part 2
Part of the Fundamentals section of Coddy's JavaScript journey — lesson 19 of 77.
Logical operators have a special table called "Truth table" that shows what the combination of logical operators returns.
Truth table for the && operator:
| a | b | a && b |
|---|---|---|
| false | false | false |
| false | true | false |
| true | false | false |
| true | true | true |
The only way to get a true for the && operator is if both a and b are true
Truth table for the || operator:
| a | b | a || b |
|---|---|---|
| false | false | false |
| false | true | true |
| true | false | true |
| true | true | true |
In this case, to get a true result, either a or b should be true.
Truth table for the ! operator:
| a | !a |
|---|---|
| false | true |
| true | false |
Here the value of a is reversed. If a is false then !a is true
Challenge
BeginnerYou are given a code, replace the question marks of the variables b1 and b2 so that b3 evaluates to true.
Note that
b1andb2should hold numbers. (e.g. 3, 5, 11, …)
Try it yourself
// Type your code below
let b1 = ?
let b2 = ?
let b3 = !((b1 + b2) > (b1 * b2))
// Don't change the line below
console.log(`b3 = ${b3}`)This lesson includes a short quiz. Start the lesson to answer it and track your progress.
All lessons in Fundamentals
4Operators Part 2
Logical Operators Part 1Logical Operators Part 2Recap - Simple LogicLogical Operators Part 3Type Coercion7Bill Split Calculator
Welcome MessageCalculating The Tip And Total2Variables
NumbersStringBooleanNaming ConventionsEmpty VariablesRecap - Initialize VariablesConstants3Operators Part 1
Arithmetic OperatorsModulo OperatorArithmetic ShortcutsComparison OperatorsStrict vs Loose EqualityRecap - Simple Math6Basic IO
OutputOutput with VariablesType Conversion - Part 1Type Conversion - Part 2Recap - Till 120Recap - True or False