5/13 TIL: Go & JS hashmap

• hashmap improves run time complexities
• hashMap equivalent in Javascript

let map = new Map()
map.set(key, value)
map.has(key) // true or false
map.get(key)
map.delete(key)

• hashMap equivalent in Go

m = make(map[int]int)
// map types are reference types so simply doing 'var m map[int]int' will not point to an initialized map and it will be nil
m[key] // set value
result := m[key] // get value
_, ok := m[key] // returns true or false in the second param
delete(m, key)

• discrete math intro
  • set-roster vs. set-builder notation
  • set-builder example: { x ∈ reals | x ≥ 2 and x ≤ 6 }