Commonly used methods for judging empty strings, arrays, and objects in JS

empty string

const string = ''

• !string return true
• string.length === 0 return true

empty array

const arr =[]

• arr.length === 0 return true

empty object

const obj ={
    
    }

• JSON.stringify(obj) === '{}' return true
• Object.keys(obj).length === 0 return true

==================There are better ways to judge, please leave a message to add

Also attached is a comparison chart of all data types