Truthiness and Falsiness in JavaScript

JavaScript has ‘truthiness’ and ‘falsiness’.

Things that are “falsey”:

• null
• undefined
• false
• 0

Things that are “truthy”

• function() {}
• '' (empty string)
• 'any other string'
• true
• 1 (or any number, apart from 0)
• [] (empty array)
• {} (new object)
• Object