const bestFruit = 'avocado'
const worstFruit = ''

if (bestFruit)  // true
if (worstFruit) // false
if (bestFruit / 2)  // false (NaN)

let mango
let watermelon = null

if (mango)      // false
if (watermelon) // false

const myFruit = {}
const allMyFruits = []

if (myFruit)        // true
if (allMyFruits)    // true