The Right Way To Log Objects in Node.js
March 01, 2021 • 2 min read
The problem
We want to log in to the console this deeply nested JavaScript Object:
const person = {
name: "Joe",
age: 24,
sayHi: function () {
console.log("Hi!");
},
friend: {
name: "Sarah",
age: 26,
friend: {
name: "Peter",
age: 39,
friend: {
name: "Sarah",
age: 26,
friend: {
name: "Annie",
age: 21,
},
},
},
},
};
A Naive Solution
The common beginner mistake is to just put it through the most basic logging tool that the language provides: console.log. However, we have limited depth logging, makingfriend on the third level just appear as [Object]:
Console.log: Hidden third level as friend: [Object].
A Hacky Solution
A trick I’ve used in the past is to put it through JSON.stringify with two extra arguments:
console.log(JSON.stringify(person, null, 2));
You can read about what these do in MDN.
But this approach carries some problems:
- Functions will disappear from the output.
- You won’t get syntax highlighting, as you’re basically logging a formatted string.
JSON.stringify: no colors and… where’s is sayHi()??
A (BETTER) SOLUTION
Use
console.dir(person, { depth: null });
That will show all nested objects, including functions, with syntax highlighting.
