JavaScript Data Types & Conditionals

🎱 The Eight Data Types

Fill in the 7 Primitive Data Types:

number - Example: _________________
string - Example: _________________
boolean - Values: _________ or _________
_________________ - Variable declared but not assigned
_________________ - Intentionally empty value
symbol - Used for: _________________
bigint - Used for: _________________

The 1 Non-Primitive Data Type:

8. _________________ - Includes arrays, functions, and more complex data

💡 Remember: Which data type is NOT primitive? _________________

📝 Working with Strings

Three Types of Quotes:

Type	Symbol	Special Feature
Single quotes	_____	Basic string
Double quotes	_____	Basic string
Backticks	_____	Template literals - allows _________________

Embedding Variables in Strings:

let name = "Alice";
let age = 25;
// Old way (concatenation):
let message1 = "Hello, " + _______ + "! You are " + _______ + " years old.";

// Modern way (template literals):
let message2 = ___Hello, ${_______}! You are ${_______} years old.___;
            

🔧 Common String Methods

Fill in what each method does:

Method	What it does	Example Result
`.length`	_________________________	"Hello".length = _____
`.toUpperCase()`	_________________________	"hello".toUpperCase() = _________
`.toLowerCase()`	_________________________	"HELLO".toLowerCase() = _________
`.slice(start, end)`	_________________________	"JavaScript".slice(0, 4) = _________
`.replace(old, new)`	_________________________	"Hi there".replace("Hi", "Hey") = _____________
`.indexOf(text)`	_________________________	"Hello World".indexOf("World") = _____

🚪 Escape Characters

Complete the common escape sequences:

\n = _________________
\t = _________________
\\ = _________________
\" = _________________
\' = _________________

⚖️ Comparison Operators

Operator	Name	Example	Result
`==`	Equal (loose)	5 == "5"	_________
`===`	Equal (strict)	5 === "5"	_________
`!=`	_________________	5 != 3	_________
`!==`	_________________	5 !== "5"	_________
`>`	_________________	10 > 5	_________
`<`	_________________	5 < 10	_________

⚠️ Best Practice: Always use _______ for comparisons unless you have a specific reason not to!

🔀 Logical Operators

The Three Logical Operators:

&& means _________ - Both conditions must be _________
|| means _________ - At least one condition must be _________
! means _________ - Flips the boolean value

Practice: What's the result?

let age = 25;
let hasLicense = true;
let isWeekend = false;

age >= 16 && hasLicense     // Result: _________
age < 16 || !hasLicense     // Result: _________
isWeekend || age > 20       // Result: _________
!(age < 18)                 // Result: _________
                

✅❌ Truthy vs Falsy Values

❌ The 6 Falsy Values (memorize these!):

_________
_________ (the number)
_________ (empty string)
_________
_________
_________ (Not a Number)

✅ Everything else is Truthy!

Including:

"false" (the string)
"0" (the string)
[] (empty array)
{} (empty object)
Any number except 0
Any non-empty string

🚦 Conditionals

If/Else Statement Syntax:

if (_________condition_________) {
    // code if true
} else if (_________another condition_________) {
    // code if second condition true
} else {
    // code if all conditions false
}
            

Switch Statement Syntax:

switch(_________variable_________) {
    case _________value1_________:
        // code for value1
        _________;  // Don't forget this!
    case _________value2_________:
        // code for value2
        _________;
    default:
        // code if no match
}
            

Ternary Operator Syntax:

let result = condition ? _____ifTrue_____ : _____ifFalse_____;

// Example:
let message = age >= 18 ? "Adult" : "Minor";
            

🪆 Nesting

What is nesting? _________________________________________

_________________________________________

⚠️ Warning: Try to keep nesting under _____ levels deep for readability!

💻 In-Class Exercises

Exercise 1: Hello World

Complete the function to return "Hello, World!":

function helloWorld() {
    _________________________
}
                

Exercise 2: Add Numbers

Complete the function to add two numbers:

function add(a, b) {
    _________________________
}
                

📚 Homework Exercises (Due Next Class)

Exercise	Description	Key Concepts
03_numberChecker	Check properties of numbers	_________________
04_mathEquations	Solve math problems	_________________
05_joinStrings	Concatenate strings	_________________

📋 Quick Reference

Common Patterns:

Check if exists: if (variable) {...}
Default value: let x = input || "default"
Range check: if (x >= min && x <= max)

Debugging Tips:

Use console.log() liberally
Check typeof variable
Test truthy/falsy with !!value

📝 Additional Notes

Use this space for any additional notes during the lecture:

JavaScript Data Types & Conditionals - Guided Notes

🎱 The Eight Data Types

Fill in the 7 Primitive Data Types:

The 1 Non-Primitive Data Type:

📝 Working with Strings

Three Types of Quotes:

Embedding Variables in Strings:

🔧 Common String Methods

🚪 Escape Characters

⚖️ Comparison Operators

🔀 Logical Operators

The Three Logical Operators:

Practice: What's the result?

✅❌ Truthy vs Falsy Values

❌ The 6 Falsy Values (memorize these!):

✅ Everything else is Truthy!

🚦 Conditionals

If/Else Statement Syntax:

Switch Statement Syntax:

Ternary Operator Syntax:

🪆 Nesting

💻 In-Class Exercises

Exercise 1: Hello World

Exercise 2: Add Numbers

📚 Homework Exercises (Due Next Class)

📋 Quick Reference

Common Patterns:

Debugging Tips:

📝 Additional Notes