Is Value an Object

#javascript #snippets

Little function to check if a value is an object:

function isObject(val){
  return (
    val != null && 
    typeof val === 'object' && 
    Array.isArray(val) === false
  );
}

Notice that Date, RegExp, etc.. will pass the check.

Top comments (5)

Pacharapol Withayasakpunt • Mar 24 '20 • Edited

For "plain" object, I rely on

function isObject(val){
  return (
    !!val && 
    typeof val === 'object' && 
    val.constructor === Object  // Or val.toString() === '[object Object]'
  );
}

Ionel Cristian Lupu • Mar 25 '20 • Edited

This won't work for class instances:

class User{}
const user = new User;
isObject(user); //false

Pacharapol Withayasakpunt • Mar 25 '20

This is just what "plain" object is.

Hao • Mar 25 '20

Or abuse JSON.stringify

const isObject = val => JSON.stringify(val).startsWith('{');

Keff • Mar 25 '20

Nice! Haven't seen this approach before :)

DEV Community

Is Value an Object

Top comments (5)

Read next

Evaluating Medical Retrieval-Augmented Generation (RAG) with NVIDIA AI Endpoints and Ragas

Deploying Docs-as-Code on AWS: Building Dynamic Documentation Sites in MkDocs and Docusaurus

Best Version Control Practices Every React Development Team Needs To Know

Top React Native Libraries for Production-Ready Applications