In memory storage
We are almost finished with the City Explorer project for this module. Last lab we focused on refactoring the code base of both our front-end and back-end. This topic matters as it relates to understanding how in memory storage work so we can implement it in our app.
Understanding the JavaScript Call Stack
What is a ‘call’?
It is a function invocation.
How many ‘calls’ can happen at once?
One at a time, from top to bottom.
What does LIFO mean?
Last In, First Out (LIFO). Which is a principle to temporarily store and manage function invocation.
Draw an example of a call stack and the functions that would need to be invoked to generate that call stack.
function firstFunction(){
console.log("Hello from firstFunction");
}
function secondFunction(){
firstFunction();
console.log("The end from secondFunction");
}
secondFunction();
What causes a Stack Overflow?
It happens when there is a recursive function, which is a function that calls itself without an exit point. The browser has a maximum stack call that it can accommodate before throwing a stack error. (e.g.)
function callMyself(){
callMyself();
}
callMyself();
JavaScript error messages
What is a ‘reference error’?
When we try to use a variables that are not yet declared.
What is a ‘syntax error’?
When we have something that cannot be parsed in terms of syntax
What is a ‘range error’?
When we try to manipulate an object with some kind of length and we give it an invalid length.
What is a ‘type error’?
When the types we are trying to use or access are incompatible.
What is a breakpoint?
It is a feature in our developer tools that we use to pause our JavaScript code at certain regions for debugging purposes.
What does the word ‘debugger’ do in your code?
It stops the execution of JavaScript. Sets a breakpoint in the debugger.
Things I want to know more about
- I would like to know more about how to debug efficiently. Would like to learn and practice debugging techniques in VS code and using our browser’s developer tools.