Advanced JavaScript for All

Intermdiate Javascript

This session delves into mid-level JavaScript concepts, providing a deeper understanding of core JavaScript behaviors. By mastering these foundational concepts, you'll be better equipped to reason about complex problems and optimize your coding practices.

Topics Covered

• Pass by Value
  Primitive data types in JavaScript, such as numbers, strings, and booleans, are passed by value when used in functions. This means that when you pass a primitive to a function, the original value is not altered because a copy of the value is passed. Understanding this concept ensures you're aware of how changes within functions don't impact the original data.
  
  
• Pass by Reference
  Non-primitive data types (such as arrays and objects) are passed by reference. This means that when you pass an object or an array to a function, the function operates directly on the original data. Any modifications inside the function affect the original array or object. This concept is essential to understanding how mutable data behaves differently from immutable types in JavaScript.
  
  
• Function Prototype
  The prototype is the mechanism by which JavaScript objects inherit properties and methods from other objects. Functions themselves are objects, and thus have prototypes. You’ll learn how to use function prototypes to add methods and properties to the prototype chain, allowing all instances of a function to share common behaviors. This knowledge is crucial for object-oriented programming in JavaScript.
  
  
• Closures
  A closure is a function that retains access to variables from its lexical scope, even after the outer function has finished executing. Closures are a powerful feature of JavaScript, enabling functionality such as data encapsulation, creating private variables, and implementing callbacks in asynchronous operations. Understanding closures is crucial for mastering JavaScript’s behavior in event-driven programming and managing state.

• Hoisting
  JavaScript hoisting refers to the behavior where variable and function declarations are moved to the top of their respective scopes during execution. It’s important to understand that only declarations are hoisted, not initializations. For example, a function declaration can be called before its definition, but variables initialized with let and const will throw an error if accessed before declaration. This concept helps you avoid common pitfalls related to the sequence of execution in JavaScript.