Welcome

Right now, I'm just hosting a few notes & diagrams here.

Jupyter Notebook Architecture

Source: https://jupyter.readthedocs.io/en/latest/architecture/how_jupyter_ipython_work.html

Edit | Edit As New

Coggle.it of Data Products

https://coggle.it/diagram/XaYGjeAbJffXLuIV/t/-

Javascript

Small things

• " or ' 🤷

Functions have an 'arguments' object

function sum() {
  var sum = 0;
  for(var i = 0; i < arguments.length; i++) {
    sum += arguments[i];
  }
  return sum;
}
sum(1, 2, 3, 4); // -> 10

How do values/variables evaluate as boolean?

• false == false
• null == false
• undefined == false
• 0 == false
• '' == false
• person.undefinedProperty == false

|| (or) returns the first truthy or last value in the expression

This is useful in assignment statements.

person.meetup = person.meetup || defaults.meetup || 'YYCJS';

Equality

• Abstract (double): checks if VALUES are equal
• Strict (triple): checks if VALUES and TYPES are equal Note: Objects are always compared by their reference. https://developer.mozilla.org/en-US/docs/Web/JavaScript/Equality_comparisons_and_sameness#A_model_for_understanding_equality_comparisons

Scope

• var: Allows function scope. All else is global.
• let: Allows block scope.
• cost: Allows block scope. Cannot be changed at runtime.
• (without var/let/cost):
  • Browser: Global scope, added to 'window' object
  • Node: Global scope, within a module