How to test for an empty object in JavaScript
Today I had the need to check if an object was empty.
Since in JavaScript objects are compared by reference, we can’t do a simple comparison like this:
const obj = {}
if (obj === {}) {
//no
}
The solution is to pass the object to the built-in method Object.keys()
and to check if the object constructor is Object
:
const obj = {}
Object.keys(obj).length === 0 && obj.constructor === Object
It’s important to add the second check, to avoid false positives.
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