Javascript Basics

A scripting language embedded in web browsers for client-side scripting.

The standard that JavaScript was standardized as in 1997.

Syntax, keywords, operators, and built-in objects.

Using the <script> tag with the src attribute.

Keywords, operators, values, and expressions.

Words that have special significance in the JavaScript language.

Special characters that perform an operation on one or more operands.

Number, string, boolean, object, function, symbol, null and undefined

A container where data can be stored and retrieved later.

A block of code designed to perform a particular task, and returns a value.

Enables interactivity and faster web experiences directly in the browser, reducing reliance on server-side processing.

Writing directly within HTML using <script> tags or linking external .js files.

Text strings, numbers, booleans, undefined, and null.

Units of code that produce a single value when evaluated.

A series of instructions executed in order.

Spaces, tabs, and line breaks that improve code readability.

Allows same script use across pages, keeps HTML clean, eases updates.

Declared with 'let', can change. Declared with 'const', stays fixed.

console.log() to browser console, alert() for pop-up, innerText to HTML element.

Determines variable accessibility; either global (everywhere) or local (in function).

A way to store multiple pieces of related data in a structured format, like a container.

Describe the characteristics of an object, such as color, brand, and model for a Car object.

Define actions that an object can perform, like start(), stop(), and accelerate() for a Car object.

Grouping everything related to a concept or entity in one place.

Using objectName.propertyName to access the property value.

Using objectName['propertyName'] to access the property value.

Objects in JavaScript are dynamic, Properties can be added, modified, and removed at any time.

String, Number, Boolean, Object, Date, Array, RegExp, Math, Error.

Built-in array that stores multiple values in a single variable.

Date, time, and timezone information.

Describes the characteristics of an object.

Define what an object can do.

A built-in object which can store different data types (numbers, strings, objects, etc.). Elements are automatically indexed starting from 0

Accesses property values using a dot.

Accesses property values using square brackets.

Used with Date and Error. Avoid with String, Number, or Boolean.

A JavaScript Date object provides methods to extract the year as four digits

A JavaScript Date object provides methods to extract the month as an index number (0-11)

A JavaScript Date object provides methods to extract the day as a number (1-31)

Directs the flow of a program by allowing code execution based on conditions or repetitions.

Evaluates a condition; if true, executes code.

Extends "if" to execute alternative code when the condition is false.

Provides multiple execution paths based on different conditions.

Repeatedly executes a block of code as long as a condition is true.

Executes code while a condition remains true

Executes the code block once, then repeats as long as the condition is true.

Exits a loop prematurely when a specified condition is met.

Skips one iteration of a loop and continues with the next.

Control structures determine the order in which statements are executed in a program.

Adds a conditional execution path when the initial 'if' condition is false.

A loop that executes the code block at least once, and then continues as long as the condition is true.

A statement in a switch block that executes if none of the case values match the switch expression.

A construct containing a test condition and statements that execute repeatedly while the condition is met.

Sets the initial value of a loop's counter variable.

An expression evaluated before each loop iteration; loop continues if it returns true.

A statement that updates a value in the test condition, preventing infinite loops.

The browser organizes web page components into a hierarchical tree

Enables dynamic webpage changes without reloading, allows JavaScript interaction with HTML and CSS, and is essential for interactive web applications.

The top-level DOM object providing properties describing the user's monitor resolution in pixels.

Total screen width in pixels.

Total screen height in pixels.

Available screen width, excluding system UI elements (pixels).

Available screen height, excluding system UI elements (pixels).

Bit value indicating the color range (e.g., 8-bit: 256 colors, 32-bit: billions of colors).

Displays a simple alert box with a message and an 'OK' button.

Displays a confirmation box with 'OK' and 'Cancel' buttons, returning true for 'OK' and false for 'Cancel'.

A method that displays a prompt box with a text input field, returning the input value with 'OK' or null with 'Cancel'.

Child objects of the document object, represented as arrays corresponding to HTML elements.

Modifies a specific element dynamically by retrieving a single element by its id.

Changes properties for multiple elements of the same type, by retrieving all elements with the given tag name.

Applies styles or modifications to multiple elements at once by retrieving all elements a specific class.

A method to insert or change HTML content within an element.

A method to insert or change only plain text within an element, ignoring HTML tags.

Adds attributes to an HTML element, enabling dynamic modifications to the DOM.

Functions that are executed when a particular event happens.