Data type double assertion

I need to check if the data type of the variable is double from the response. Please assist if the code is correct ?
“Dat”: {
“C”: [
{
“T”: “dfd”,
“C”: “D”,
“Amount”: {
“Amount”: 23.7
}
},

the code written is :
pm.expect(json.Dat.C[0].Amount.Amount).to.be.a(‘double’);

I am getting failed and the reason is :AssertionError: expected 23.7 to be a double…

Is the mean that 23.7 derived in the response isn’t it double and they developed with some other data type? Please guide

Postman uses the Chaijs library for assertions.

Expect / Should - Chai (chaijs.com)

In particular…

Method a

Which in turn uses “typedetect”.

GitHub - chaijs/type-detect: Improved typeof detection for node.js and the browser.

I can’t see double anywhere in that list, but as its not erroring I’m not 100% sure.

What does typeof think that variable is?

console.log(typeof(json.Dat.C[0].Amount.Amount));