Introduction to Hoisting in JavaScript

Key Points

• There is a variable x with a value of 7.
• There is a function getName that calls console.log(x).
• Expected output: 7.

Hoisting in JavaScript

• In JavaScript, you can access variables and functions even before they are declared.
• Example: Calling getName() prints 7.
• This is a specific behavior called hoisting.

Error Handling

• If you try to access x without setting a value, you'll get an "undefined" error.
• In JavaScript, accessing a variable before declaring it returns "undefined".

Characteristics of Function Declarations

• getName is a function, but if converted to an arrow function, it will behave like a variable.
• According to hoisting rules, it will not be treated as a function.

Memory Allocation

• When JavaScript starts running the code, memory is allocated for functions and variables.
• In memory, "undefined" is a special placeholder for variables.

Call Stack and Execution Context

• When a function is called, a new execution context is created.
• It is added to the call stack and removed when the function finishes.

Conclusion

• Hoisting is an important aspect of JavaScript, determining when and how we can access variables and functions.
• Keep this in mind next time you discuss hoisting.

Next Classes

• Detailed discussion on functions in JavaScript will be conducted.
• Don’t forget to watch previous videos to learn more about this topic.