Frontend Interview Tips

  1. Falsy Values

has 6 types: undefined null Nan - not a number 0 - zero '' - empty strings false

  1. const vs let vs var

all variable types block scope(ES6): const - constant value (can reaasign value in objects and arrays) let - reassigning value

lexical scope(deprecated): var - reassigning value

  1. Double Equal vs Triple Equal

javascript type value vs value and type

value1 = 5 value2 = '5'

(value1 == value2) //true (value1 === value2) //false