JavaScript Display Objects


How to Display JavaScript Objects?

Displaying a JavaScript object will output [object Object].

Example

const person = {
  name: "John",
  age: 30,
  city: "New York"
};

document.getElementById("demo").innerHTML = person;
Try it Yourself »

Some common solutions to display JavaScript objects are:

  • Displaying the Object Properties by name
  • Displaying the Object Properties in a Loop
  • Displaying the Object using Object.values()
  • Displaying the Object using JSON.stringify()


Displaying Object Properties

The properties of an object can be displayed as a string:

Example

const person = {
  name: "John",
  age: 30,
  city: "New York"
};

document.getElementById("demo").innerHTML =
person.name + "," + person.age + "," + person.city;
Try it Yourself »

Displaying the Object in a Loop

The properties of an object can be collected in a loop:

Example

const person = {
  name: "John",
  age: 30,
  city: "New York"
};

let txt = "";
for (let x in person) {
txt += person[x] + " ";
};

document.getElementById("demo").innerHTML = txt;
Try it Yourself »

You must use person[x] in the loop.

person.x will not work (Because x is a variable).


Using Object.values()

Any JavaScript object can be converted to an array using Object.values():

const person = {
  name: "John",
  age: 30,
  city: "New York"
};

const myArray = Object.values(person);

myArray is now a JavaScript array, ready to be displayed:

Example

const person = {
  name: "John",
  age: 30,
  city: "New York"
};

const myArray = Object.values(person);
document.getElementById("demo").innerHTML = myArray;
Try it Yourself »

Object.values() is supported in all major browsers since 2016.

54 (2016) 14 (2016) 47 (2016) 10 (2016) 41 (2016)


Using JSON.stringify()

Any JavaScript object can be stringified (converted to a string) with the JavaScript function JSON.stringify():

const person = {
  name: "John",
  age: 30,
  city: "New York"
};

let myString = JSON.stringify(person);

myString is now a JavaScript string, ready to be displayed:

Example

const person = {
  name: "John",
  age: 30,
  city: "New York"
};

let myString = JSON.stringify(person);
document.getElementById("demo").innerHTML = myString;
Try it Yourself »

The result will be a string following the JSON notation:

{"name":"John","age":50,"city":"New York"}

JSON.stringify() is included in JavaScript and supported in all major browsers.


Stringify Dates

JSON.stringify converts dates into strings:

Example

const person = {
  name: "John",
  today: new Date()
};

let myString = JSON.stringify(person);
document.getElementById("demo").innerHTML = myString;
Try it Yourself »

Stringify Functions

JSON.stringify will not stringify functions:

Example

const person = {
  name: "John",
  age: function () {return 30;}
};

let myString = JSON.stringify(person);
document.getElementById("demo").innerHTML = myString;
Try it Yourself »

This can be "fixed" if you convert the functions into strings before stringifying.

Example

const person = {
  name: "John",
  age: function () {return 30;}
};
person.age = person.age.toString();

let myString = JSON.stringify(person);
document.getElementById("demo").innerHTML = myString;
Try it Yourself »

Stringify Arrays

It is also possible to stringify JavaScript arrays:

Example

const arr = ["John", "Peter", "Sally", "Jane"];

let myString = JSON.stringify(arr);
document.getElementById("demo").innerHTML = myString;
Try it Yourself »

The result will be a string following the JSON notation:

["John","Peter","Sally","Jane"]


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