Master numbers and strings with this guide. Enhance your coding skills by understanding data types and their applications in programming.

Numbers And Strings

[00:00] All right. Let's go ahead and get this one done. So we have our variable named price. We're going to set that to $29.99. That's going to have a type of number.

[00:09] Now, we can be explicit and say number is our type, to be very explicit. We'll talk about inference here in the next exercise. So this is absolutely gotta be assigned to a number. It can't be assigned to anything else. Hi there.

[00:25] We can't assign it to anything else. We can do this as anything that that the ghost text is saying. You don't really wanna do that normally. So we're gonna not do that and instead we're gonna set it to 2999. Then we're gonna create a product name and this we are going to also do that colon and then the the name of the type.

[00:45] The name of the type is string. You don't need that extra space there after the colon. You definitely need the colon though. That changes things entirely. It would change the variable name.

[00:54] But, yeah. So we're gonna do colon string equals, the typescript guide. And this means we can't set it to a number because now a typescript is like, hold on. Hold on. You said the product name was a string, but now you're over here assigning it to a number.

[01:08] Come on, man. Like, what's going on here? So we're gonna assign it to a string. And then we can create a, quality is a number and, set that to a 100. And then we're gonna create a description, which is a string that's a template literal.

[01:22] So it's still same same sort of string even though this one's single quote and this one's a back tick with interpolated values and everything. This still ultimately is a string. So we can assign it as a string and give it that very explicit type. And then, we take care of that. Let's uncomment these and uncomment this.

[01:43] And we take a look at our results here. We've got our price as $29.99. TypeScript guide quality is 100. And here's the, results of our description. Product typescript guide.

[01:55] Price, $29.99. In stock, 100. And then here are all of our exports which will be used by the test. So there you go. You can explicitly say what type a variable can be.

[02:06] And the cool thing about this too is if I were to say, hey. Let this price be a number and it is assigned to this. Now later on, I can't say price equals, $30.99. TypeScript is gonna warn me about that. This is the value of, TypeScript and and being able to specify the type of something.

[02:26] We're gonna actually improve this, fair bit because there's a lot of typing, pun intended, to make all of this work. And, TypeScript's a little bit smarter than that. So we'll take a look at that here in the next exercise. But for now, well done on this one.

[00:00] Let's get into numbers and strings. Here, we've got a product cataloging system. And we need to have a couple of variables that you need to create of two different data types. And you've actually already seen these data types before, but we're gonna be a little bit more formal in how we talk about them in this exercise. So you've got strings, numbers, and you're gonna play around with, those a little bit.

[00:22] We're gonna play around with some interpolation and stuff. You'll have some console logs. I think you're gonna have a good time with this one, so I'll just let you do it. Have fun.

Learning to program can feel overwhelming. There are countless tutorials, boot camps, and YouTube videos all pulling you in different directions, and most of them assume you already know something.

The result? Gaps in your understanding that haunt you for years. You memorize syntax without understanding what it means. You copy-paste code that works but can't explain why. When something breaks, you're stuck because you never built the mental model to reason about what's happening underneath.

The Programming Foundations Workshop is your ground-zero start to becoming a software developer. Built with TypeScript from the very first line, it takes you from zero prior programming experience through expressions, variables, types, functions, and beyond-- equipping you with the foundational knowledge that every concept in web development builds on.

No prior programming knowledge is required. If you can open an editor and run the workshop app, you're ready. And because this is how software is built today, you'll learn alongside AI-assisted tooling from the start-- building the skills to write, review, and understand code in a modern development workflow.

## Expressions & Output

Every program needs a way to tell you what it's doing. Without output, you're flying blind-- writing code with no way to verify it works. This is the very first skill you need as a developer.

In this section, you'll get your programs talking back to you while learning the building blocks of every piece of code you'll ever write:

- Outputting values with `console.log`
- String expressions and concatenation
- Number expressions and arithmetic operators
- Escaping special characters in strings
- Template literals with interpolation and multiline support

## Variables

Hardcoded values can only get you so far. Real programs need to store, reference, and update data as they run. Without a solid understanding of how variables work, you'll constantly be confused by unexpected behavior.

Variables are foundational to every program you'll ever write. Here you'll learn how to declare them, when to use each type, and a critical nuance that trips up even experienced developers:

- Declaring variables with `let` and `const`
- Naming conventions and casing (camelCase, SCREAMING_SNAKE_CASE)
- Reassigning values with `let` and compound operators like `+=`
- The important distinction between reassignment and mutation
- Why `const` doesn't always mean the value can't change

## Primitive Types

JavaScript has types whether you think about them or not. Every value in every variable carries a type, and ignoring that fact leads to bugs that are hard to track down. TypeScript makes these types explicit, catching entire categories of errors before your code ever runs.

This section introduces you to all seven primitive types and how TypeScript helps you work with them safely:

- Explicit type annotations with `number`, `string`, and `boolean`
- The difference between `null` and `undefined`
- Special types: `bigint` for arbitrarily large numbers and `symbol` for unique identifiers
- Type coercion and why it can surprise you
- Floating-point precision and practical considerations for working with numbers

## Comparisons & Boolean Logic

Making decisions is at the heart of every program. Should this button be enabled? Does this user have access? Is the cart empty? All of these questions boil down to comparisons and boolean logic.

Getting comparisons wrong leads to subtle bugs that are painful to debug. This section gives you the tools to write conditions that behave exactly as you'd expect:

- Loose equality (`==`) vs. strict equality (`===`) and why you should almost always use strict
- Not-equal, greater-than, and less-than-or-equal-to operators
- Combining conditions with logical AND (`&&`), OR (`||`), and NOT (`!`)
- Order of operations with logical operators
- Using parentheses to make complex conditions explicit

## Truthiness & Falsiness

JavaScript has a unique feature where every value has an inherent "truthiness" or "falsiness." This isn't a bug-- it's one of the most practical features of the language once you understand it. But misunderstanding it leads to some of the most confusing behavior new developers encounter.

Here you'll learn which values are truthy, which are falsy, and how to use this knowledge to write cleaner conditional logic:

- Coercing values to booleans with the `Boolean` constructor
- The double-not (`!!`) operator and when to use it
- Falsy values: `0`, `""`, `null`, `undefined`, `false`, and `NaN`
- Practical patterns like checking array length and optional values
- Avoiding common pitfalls with logical operators and coercion

## Functions

Up to this point, your programs run top to bottom and that's it. Functions change everything. They let you take a chunk of code, put it somewhere reusable, and call it from anywhere-- with different inputs each time.

Functions are the single most important building block for organizing and scaling your programs. This section takes you from writing your first function through passing functions as arguments to other functions:

- Function declarations with the `function` keyword
- Accepting parameters and specifying their types
- Return values and TypeScript's return type inference
- Arrow functions and implicit returns
- Passing functions as arguments to other functions
- Documenting your functions with JSDoc

## Type Inference & Arrow Functions

TypeScript is smart. You don't have to type everything explicitly-- TypeScript can often figure out the types for you by looking at your code. Knowing when to lean on inference and when to be explicit is a skill that makes your code cleaner and your development faster.

This section also covers arrow functions, a concise alternative syntax you'll see everywhere in modern JavaScript and TypeScript:

- How TypeScript infers return types from your function body
- When explicit return types help catch bugs earlier
- Converting function declarations to arrow functions
- Implicit returns for single-expression functions
- The hoisting difference between declarations and expressions
- Function expressions as first-class values

## Void & Never

Not every function returns something useful, and some code paths should never be reached. TypeScript has dedicated types for both of these situations, and understanding them helps you write more precise, self-documenting code.

This section introduces two TypeScript-specific concepts that complete your understanding of the type system's fundamentals:

- The `void` type for functions that don't return a value
- How `void` relates to `undefined` in practice
- The `never` type for functions that throw errors or never return
- Using `never` to enforce exhaustive checks
- Throwing errors to halt execution and signal failures
- Practical patterns for input validation with error throwing

Programming Foundations

Structured Data

Type Safety

Object Oriented TypeScript

Advanced TypeScript

Practical TypeScript: Foundations to Fluency

Master programming basics with our Introduction to Programming Foundations. Perfect for beginners eager to start coding and build essential skills.

Intro to Introduction To Programming Foundations

Introduction to Programming Foundations

Intro to Expressions And Output

Hello World

Escaping Strings

Strings

Numbers

Template Literals

Discover the art of taking effective breaks to boost productivity and mental clarity. Learn techniques to recharge and enhance focus in your daily routine.

Break

1. Expressions And Output

Intro to Variables

Discover the key differences between let and const in JavaScript. Optimize your code with these essential ES6 variable declarations.

Let And Const

Explore the key differences between reassignment and mutation in programming. Enhance your coding skills with clear insights and practical examples.

Reassignment Vs Mutation

Discover effective strategies to break bad habits and boost productivity. Transform your routine with actionable tips for lasting change.

Break Variables

2. Variables

Discover the basics of primitive types in programming. Understand integers, floats, booleans, and more to enhance your coding skills.

Intro to Primitive Types

Discover key differences and similarities with our in-depth comparisons. Make informed decisions with clear insights and expert analysis.

Comparisons

Master Booleans and comparisons in programming. Enhance your coding skills with clear examples and practical applications. Perfect for beginners!

Booleans And Comparisons

Explore the differences between null and undefined in JavaScript. Master these concepts to enhance your coding skills and avoid common errors.

Null And Undefined

Explore Bigint and Symbol in JavaScript. Enhance your coding skills with these powerful data types for handling large numbers and unique identifiers.

Bigint And Symbol

Master JavaScript truthy and falsy values with this guide. Enhance coding skills by understanding data types and logical operations.

Truthy Falsy

Break Primitive Types

3. Primitive Types

Master control flow basics in programming. Enhance your coding skills with loops, conditionals, and more. Perfect for beginners!

Intro to Control Flow

Master conditional logic by building a grade calculator that maps numeric scores to letter grades. Sharpen your programming skills today!

Conditionals

Master switch statements in programming. Simplify code logic, enhance readability, and boost efficiency with this essential guide.

Switch Statements

Master loops in programming! Enhance your coding skills with efficient loop techniques. Perfect for beginners and pros seeking to optimize code.

Loops

Master nested loops in programming to enhance your coding skills. Discover efficient techniques and practical examples for optimal performance.

Nested Loops

Master the ternary operator for concise code. Discover its syntax, benefits, and examples to enhance your programming skills efficiently.

Ternary Operator

Discover common errors, their causes, and solutions. Enhance your skills by learning to identify and fix mistakes effectively.

Errors

Break Control Flow

4. Control Flow

Master the basics of functions in programming. Enhance your coding skills with clear examples and practical insights. Perfect for beginners!

Programming Foundations

Programming Foundations

Transcript

Numbers And Strings

Transcript