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982 B

Seeker of Truth

Truthy and Falsy

In JS, all values are either truthy or falsy, this means if used in a condition, truthy values will validate the condition while falsy values would not.

Here is the list of falsy values:

  • undefined and null
  • the numbers 0 and NaN
  • the empty string ''
  • and the boolean false of course

All other values are truthy, note that empty arrays and empty objects are truthy, but the empty string is not.

if ('') {
  console.log('Since empty string are falsy, this will never log')
}

if ('hello') {
  console.log('this will always log as the string is not empty')
}

Operator !

The ! (NOT operator) can be used to convert a truthy value to false or a falsy value to true.

example:

let money = 0
let noMoney = !money

console.log(noMoney) // true

In this case, 0 is falsy, so the ! return the value true

Instructions

R

let truth = 0

if (!truth) {
 console.log()
}