reading-notes

Course 301, Entry 10: In memory storage

Understanding the JavaScript Call Stack

What is a ‘call’?

A call is the running of a callback function.

How many ‘calls’ can happen at once?

Calls are synchronous, running one at a time in order.

What does LIFO mean?

LIFO stand for Last In First Out. It is in reference to how items are processed based on storage.

Draw an example of a call stack and the functions that would need to be invoked to generate that call stack.

How does this fit in with the Event Loop? The callstack is a JavaScript runtime component. The event queue contains JavaScript runtime.

What causes a Stack Overflow?

A Stack Overflow occurs when a recursive function (loop) occurs without an exit. Once the stack memory allocations is exceeded, the stack error is thrown.

JavaScript error messages

What is a ‘reference error’?

A variable is used but has not yet declared.

What is a ‘syntax error’?

An error in the syntax composition. Common syntax errors are missing commas, parenthesis or bracket notation.

What is a ‘range error’?

An invalid length has been entered. No negative lengths are allowed.

What is a ‘type error’?

The data type being used is not compatible with the place in which it is being used. This can also be due to a reference error, as the type error can precursor a reference error. This is because if a variable is undefined, there is no type.

What is a breakpoint?

hitBreakpoints are stopping points in a code execution which are hit if certain conditions are met.

What does the word ‘debugger’ do in your code?

“Debugger” sets a breakpoint in the code.

Image sources: https://stackoverflow.com/questions/21596172/what-function-gets-put-into-eventloop-in-nodejs-and-js

https://medium.com/swlh/in-depth-introduction-to-call-stack-in-javascript-a07b8513bcc3

Things I want to know more about

Expanding further on the browser processes perhaps. I am not sure what is a good range of knowledge, as I know there is a lot going on.