<h1> to <h6>
Headings, from the most important (h1) to the least (h6). Use one h1 per page.
<h1>Recipes</h1>
<h2>Breakfast</h2>
<h3>Pancakes</h3>Reference
Short entries with an example for each. When you need every detail, each entry links to the official documentation.
HTML
<p>
A paragraph of text.
<p>Fresh bread every morning.</p><strong> and <em>
strong marks important words (bold); em adds spoken emphasis (italic).
<p>This is <strong>important</strong>, <em>really</em>.</p><a>
A link. href says where it goes.
<a href="https://example.org">Visit</a><img>
An image. Always add alt text that describes it.
<img src="cat.jpg" alt="A cat asleep on a chair"><ul>, <ol>, <li>
Bulleted and numbered lists. Each item is an li.
<ul>
<li>Milk</li>
<li>Eggs</li>
</ul><table>, <tr>, <th>, <td>
A table of data: rows (tr) made of header (th) and data (td) cells.
<table>
<tr><th>Day</th><th>Class</th></tr>
<tr><td>Mon</td><td>Maths</td></tr>
</table><div> and <span>
Plain containers: div for blocks, span for words inside a line.
<div class="card">Tea <span class="price">$3</span></div><label> and <input>
An input box and the label that names it. Match for and id.
<label for="name">Name</label>
<input id="name"><select> and <option>
A dropdown list of choices.
<select>
<option>Small</option>
<option>Large</option>
</select><button>
A clickable button. Inside a form it submits the form.
<button>Save</button><header>, <nav>, <main>, <footer>
Page regions that say what each part is for, which helps screen readers and search engines.
<header><h1>Shop</h1></header>
<nav><a href="#">Home</a></nav>
<main><p>Welcome!</p></main>
<footer><p>Open daily</p></footer><title> and <meta>
Page information in the head: the tab title, a search description and the phone viewport.
<head>
<title>Sunny Bakes</title>
<meta name="description" content="Fresh bread daily.">
<meta name="viewport" content="width=device-width, initial-scale=1">
</head>CSS
color
Sets the text color.
h1 { color: teal; }font-size and font-family
Set the size and typeface of text. Always end the font list with a generic family.
p { font-size: 20px; font-family: Georgia, serif; }Class and id selectors
A dot selects a class, a # selects an id.
.note { color: gray; }
#top { color: crimson; }background
Sets the background color or image of an element.
.hero { background: #fef3c7; padding: 20px; }padding
Space inside an element's border.
.card { padding: 20px; background: #eef2ff; }margin
Space outside an element's border.
.card { margin: 24px; background: #eef2ff; }border and border-radius
Draw a line around a box and round its corners.
.card { border: 2px solid navy; border-radius: 12px; padding: 12px; }display: flex
Lays out an element's children in a row (or a column).
.row { display: flex; gap: 12px; }display: grid
Places children in rows and columns.
.grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 8px; }gap
Space between the items in a flex or grid container.
.row { display: flex; gap: 24px; }@media
Applies styles only when the screen matches a condition, such as a narrow width.
@media (max-width: 600px) {
body { background: lightyellow; }
}:hover
Matches an element while the mouse pointer is over it.
a:hover { color: crimson; }transition
Animates a change in a property over time.
.btn { transition: transform 0.3s; }
.btn:hover { transform: scale(1.2); }JavaScript
console.log()
Prints values to the console for checking your work.
console.log("Total:", 42);let and const
Declare variables. Use const when the value never changes.
const tax = 0.08;
let total = 0;
total = 100 + 100 * tax;
console.log(total);function
Defines reusable code that can take inputs and return a result.
function area(w, h) {
return w * h;
}
console.log(area(3, 4));if...else
Runs code only when a condition is true, with an optional fallback.
let age = 15;
if (age >= 18) {
console.log("Adult");
} else {
console.log("Not yet");
}Arrays
Ordered lists of values. Indexes start at 0.
const colors = ["red", "green"];
colors.push("blue");
console.log(colors.length, colors[0]);for...of
Loops over every item in an array.
for (const fruit of ["apple", "pear"]) {
console.log(fruit);
}Objects
Group related values under names (properties).
const pet = { name: "Milo", age: 3 };
pet.age = 4;
console.log(pet.name, pet.age);Template literals
Strings in backticks that can include values with a dollar sign and braces.
const name = "Ada";
console.log(`Hi, ${name}!`);querySelector()
Finds the first element that matches a CSS selector.
const title = document.querySelector("h1");
title.textContent = "Found it!";addEventListener()
Runs a function when something happens, like a click.
button.addEventListener("click", () => {
button.textContent = "Clicked!";
});textContent
Reads or replaces the text inside an element.
document.querySelector("#msg").textContent = "Saved";createElement() and append()
Make a new element, then add it to the page.
const li = document.createElement("li");
li.textContent = "New item";
list.append(li);C++
std::cout
Writes text and values to the console.
std::cout << "Score: " << score << std::endl;Variables and types
Every variable has a type: int, double, bool, std::string and more.
int age = 12;
double price = 4.99;
bool ready = true;
std::string name = "Ada";if / else
Runs code when a condition is true, and other code when it isn't.
if (marks >= 40) {
std::cout << "Pass";
} else {
std::cout << "Try again";
}for loop
Repeats a block a set number of times.
for (int i = 0; i < 3; i++) {
std::cout << i;
}Functions
Named, reusable code with a return type and parameters. Define them above main.
int square(int n) {
return n * n;
}std::vector
A list that can grow. push_back adds; size counts.
std::vector<int> v = {1, 2};
v.push_back(3);
std::cout << v.size();class
A blueprint that bundles data and methods. Ends with };
class Dog {
public:
std::string name;
void bark() { std::cout << "Woof"; }
};std::cin
Reads input typed by the user.
int age;
std::cin >> age;C#
Console.WriteLine()
Prints a line of text to the console.
Console.WriteLine("Ready");Variables and types
Typed variables: int, double, bool, string and more.
int age = 12;
double price = 4.99;
bool ready = true;
string name = "Ada";String interpolation
Puts values inside text with $ and braces.
Console.WriteLine($"Total: {total}");if / else
Runs code only when a condition is true.
if (age >= 18)
{
Console.WriteLine("You can vote.");
}
else
{
Console.WriteLine("Not yet.");
}for and while
Repeat code a set number of times, or while a condition is true.
for (int i = 1; i <= 3; i++)
{
Console.WriteLine(i);
}Methods
Named, reusable code inside a class.
static int Square(int n)
{
return n * n;
}List<T> and foreach
A list that can grow; foreach visits every item.
List<string> names = new List<string>();
names.Add("Asha");
foreach (string n in names)
{
Console.WriteLine(n);
}Classes and objects
A class is a blueprint; new creates an object from it.
class Dog
{
public string Name;
}
Dog rex = new Dog();
rex.Name = "Rex";Console.ReadLine()
Reads a line of text typed by the user.
string name = Console.ReadLine();No entries match. Try a shorter word.