You can get the type of the ' person' object using the ' typeof' operator, and then use the ' keyof' operator on the result to get all its property names: In the case where the type of an object is not directly known, you can use ' typeof' to get the type of the object and then use ' keyof' on the resulting type.

Please keep in mind the distinction between values and types when using TypeScript.

' keyof' operator works on the resulting object type and provides a union of all string literals that make up its property names.

' typeof' operator works on a JavaScript value (such as a variable, constant, parameter, function, class declaration, or enum) to infer the type of the value, and.

When used together, ' keyof typeof' can be used to get the property names of an object in TypeScript, where: it doesn't differentiate plain objects from other built-in objects, except for function.The history of typeof null covers this bug in details. it is a known bug that typeof null = 'object'.It works fine for number, string, undefined, boolean, symbol, function but there are some pitfalls to watch out for when using typeof: The typeof operator is probably the first that comes to mind. Forget about typeof and instanceof, the best way to check data types is to use.All of the current native ways are imperfect (or just straight up buggy), so we are stuck rolling our own. There are no built-in ways to check data types in JavaScript that are straightforward and all-encompassing.In this post, I am going to cover what they are, when to use them, and, in my opinion, which one is the best. In JavaScript, there are 8 data types, and there are mainly 3 ways to check which type a given value is. JavaScript is such an imperfect language that you can't even rely on it for simple things like checking data types. Published on 20 May, 2022 Last updated on 23 August, 2022

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