reading-notes

Reading Notes for Codefellows!

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Code 301

Reading 10

(All My Notes are attributed/sourced from the Resources directly preceding them.)

Call Stack

Author: Mozilla and Individual Contributors

Article Source

A call stack is a mechanism for an interpreter (like the JavaScript interpreter in a web browser) to keep track of its place in a script that calls multiple functions

• When a script calls a function, the interpreter adds it to the call stack and then starts carrying out the function.

• Any functions that are called by that function are added to the call stack further up, and run where their calls are reached.

• When the current function is finished, the interpreter takes it off the stack and resumes execution where it left off in the last code listing.

• If the stack takes up more space than it had assigned to it, it results in a “stack overflow” error.

  (NOTE: All the above notes comes directly from the Article word for word)

The JavaScript Call Stack - What It Is and Why It’s Necessary

Author: Charles Freeborn

Article Source

• Understanding the call stack helps give clarity to the function hierarchy and function execution order.
• The call stack is mostly used for function calls
  • Since JavaScript is single threaded, functions execute in synchronous order
  • A stack works as a type of list following the LIFO (Last In First Out) execution sequence.
• Asynchronous JavaScript uses a callback function, an event loop, and a task queue.
• A stack overflow happens with a recursive function hits an infinite loop

JavaScript error messages && debugging

Author: Diogo Spínola

Article Source

• A bug is unexpected behavior of code that does not work as intended
• Ways to identify bugs your code:
  • Error Messages
    1. Reference Errors - trying to use variables that have yet to be declared
    2. Syntax Errors - missing, misplaced, misspelled, or extra characters in your line of code
    3. Range Errors - trying to manipulate variables outside of their scope
    4. Type Errors - trying to change the type of a variable, such as putting a string into a numeric variable
  • console.log
  • breakpoints
  • Tools to try to avoid errors:
    1. quokka
    2. eslint
    3. TypeScript
• Handling Errors
  • Try and Catch are methods designed to try to handle errors

  Additional SQL Resources

  • JavaScript errors reference on MDN

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