Why this matters: This information matters because it details functional programming and introduces Modules and require() in Node.js.
1. What is functional programming?
Functional programming is a style of building the structure and elements of computer programs that treats computation as the evaluation of mathematical functions and avoids changing-state and mutable data.
2. What is a pure function and how do we know if something is a pure function?
A pure function is also referred to as deterministic. It returns the same result if given the same arguments and it doesn’t cause observable side effects.
3. What are the benefits of a pure function?
-The code is easier to test -No mock needed
4. What is immutability?
Unchanging over time or unable to be changed at all.
5. What is Referential transparency?
Referential transparency = pure function + immutable data.
Source: https://www.youtube.com/watch?v=xHLd36QoS4k
1. What is a module?
A module is a JS file.
2. What does the word ‘require’ do?
Require passes a string in () that’s a path to the module that’s required in a given file.
3. How do we bring another module into the file the we are working in?
In the module file, export what you want to be available outside of the module:
module.exports = name of things to export;
In the receiving file, set a variable:
let variableName = require('file name');
4. What do we have to do to make a module available?
module.exports = name of things to export;
Nothing at the moment!
Why this matters: This information matters because it outlines the call stack and terminology needed to understand it, along with a rundown of various types of errors and debugging methods.
Source: https://www.freecodecamp.org/news/understanding-the-javascript-call-stack-861e41ae61d4
1. What is a ‘call’?
Function invocation.
2. How many ‘calls’ can happen at once?
One at a time, from top to bottom.
3. What does LIFO mean?
Last In, First Out, the principle used by call stack data structures to temporarily store and manage function invocation.
4. Draw an example of a call stack and the functions that would need to be invoked to generate that call stack.
function firstFunction(){
throw new Error('Stack Trace Error);
}
function secondFunction(){
first function();
}
function thirdFunction(){
secondFunction;
}
thirdFunction();`
5. What causes a Stack Overflow?
A stack overflow occurs when there’s a function that calls itself (a recursive function) without an exit point. The browser has a maximum stack call that it can accommodate before throwing a stack error.
Source: https://codeburst.io/javascript-error-messages-debugging-d23f84f0ae7c
1. What is a ‘reference error’?
When you try to use a variable that is not yet declared.
2. What is a ‘syntax error’?
When you have something that cannot be parsed in terms of syntax.
3. What is a ‘range error’?
When you try to manipulate an object with some kind of length and give it an invalid length. For example, an array cannot have a negative length.
4. What is a ‘type error’?
When the types (number, string, etc.) you are try9in gto use or access are incompatible, like accessing a property in an undefined type of variable.
5. What is a breakpoint?
It’s an internal stopping or pausing place in a program that allows the developer to find where bugs exist in the code. Source
6. What does the word ‘debugger’ do in your code?
Adds a breakpoint.
Nothing at the moment!