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## Introduction to JavaScript

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1. JavaScript: Basics
9Topics
|
10 Quizzes
2. JavaScript: Variables
9Topics
|
10 Quizzes
3. JavaScript: Conditional Statements
10Topics
|
11 Quizzes
4. JavaScript: Functions
10Topics
|
11 Quizzes
5. JavaScript: Scope
6Topics
|
7 Quizzes
6. JavaScript: Arrays
11Topics
|
12 Quizzes
7. JavaScript: Loops
8Topics
|
9 Quizzes
8. JavaScript: High Order Functions
3Topics
|
4 Quizzes
9. JavaScript: Iterators
5Topics
|
5 Quizzes

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Lesson 3, Topic 4
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# JavaScript: Logical Operators

##### Yasin Cakal 31 Oct 2021
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We’ll be using booleans, `true` or `false` values while working with conditionals. The logical operators are operators in JavaScript that work with boolean values. To make our conditionals more sophisticated, we can use logical operators. There are three different types of logical operators:

1. The AND operator `&&`.
2. The OR operator `||`.
3. The NOT operator `!` , also known as the bang operator.

When we use the `&&` operator, we ensure that two conditions are met:

``````if (haveCar=true && licsence = true) {
console.log('You can drive!');
} else {
console.log('Stop! You cannot drive');
}``````

Both conditions must evaluate to `true` for the complete condition to evaluate to `true` and execute when using the `&&` operator. If either condition is `false`, the `&&` condition evaluates to `false`, and the `else` block will execute.

We can use the `||` operator if we just worry about one of the conditions being `true`:

``````if (stopLight === 'red' || stopLight === 'yellow') {
console.log('Stop and Wait!');
} else {
console.log('Go!');
}``````

In `||` operator only one of the requirements must evaluate to `true` for the total statement to evaluate to `true`. If either `stopLight === 'red'` or `stopLight=== 'yellow' `evaluates to `true` in the code sample above, the `if` condition will evaluate to `true`, and the code block will execute. The second condition in a `||` statement will not be checked if the first condition evaluates to `true`. The code in the `else` expression will only run if both comparisons are `false`.

The `!` NOT operator is used to reverse or negate the value of a boolean:

``````let hungry= true;
console.log(!hungry); // Prints false

let weekend= false;
console.log(!weekend); // Prints true``````

Essentially, the `!` operator receives a `true` value and returns a `false` value, or it receives a `false` value and returns a `true` value.

In conditional statements, logical operators are frequently used to add another layer of logic to our code.

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