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propertiestypeofdeno

Accessing Object information in Deno

When using Deno 0.42.0, I find it difficult to do any type of analysis of objects by using typeof or other inspection techniques I use in JavaScript.

For example: 

const form = new FormData();
console.log(`typeof: ${ typeof form }`);

.. just returns object

Similarly, inspecting properties like: 

const form = new FormData();
console.log(`props: ${ Object.getOwnPropertyNames(form) }`);

... returns nothing.

At least instanceof does work:

const form = new FormData();
console.log(`props: ${ form instanceof FormData }`);

... returns true

Is there a way in Deno to inspect objects in real time without first knowing what the object type is?

Solution

  • It works exactly like that on the browser too.

    typeof possible return values are:

    • undefined
    • object
    • boolean
    • number
    • bigint
    • string
    • symbol
    • function

    So it's not possible for you to get another value.

    Maybe what you want is .constructor.name

    const form = new FormData();
console.log(`class: ${form.constructor.name}`); // FormData
console.log(`props: ${ form instanceof FormData }`); // true