Typescript property does not exist on type {}

property does not exist on type angular 7
property does not exist on type defaultrootstate
property does not exist on type angular 8
error ts2339: property 'data' does not exist on type 'object'.
property does not exist on type react
property does not exist on type 'appcomponent
typescript property does not exist on type 'object
property does not exist on type 'unknown'

I have the following code in Typescript. Why does the compiler throws an error?

var object = {};
Object.defineProperty(object, 'first', {
     value: 37,
     writable: false,
     enumerable: true,
     configurable: true
});
console.log('first property: ' + object.first);

js.ts(14,42): error TS2339: Property 'first' does not exist on type '{}'.

It's the same code snippet like in the documentation of mozilla (examples section).

Another way is to do interface, so compiler will know that property exists.

interface IFirst{
  first:number;
}


let object = {} as IFirst;
Object.defineProperty(object, 'first', {
  value: 37,
  writable: false,
  enumerable: true,
  configurable: true
});
console.log('first property: ' + object.first);

Take a look at this question How to customize properties in TypeScript

Property does not exist on type 'object', You probably have allProviders typed as object[] as well. And property country does not exist on object . If you don't care about typing, you can declare both  Throws The property 'getBBox' does not exist on value of type 'HTMLElement'. The easiest way is to explicitly type variable as any. var outerHtmlElement: any = outerElement[0]; var coordinates = outerHtmlElement.getBBox(); Edit, late 2016. Since TypeScript 1.6 prefered casting operator is as those lines can be squqshed into elegant:

Make the object type any:

var object: any = {};

Getting error TS2339: Property does not exist on type for a valid ES6 , When compiled/transpiled through TypeScript it generates error TS2339: Property 'myclassvar' does not exist on type 'MyClass'. If the above  This seems to be similar to this issue: False "Property does not exist on type 'never'" when changing value inside callback with strictNullChecks, which is closed as a duplicate of this issue (discussion): Trade-offs in Control Flow Analysis. That discussion is pretty long, if you can't find a good solution there you can this:

That's because Typescript is a strict type language. When you create a variable and give to it a type, you can't access properties that does not exists in that type. After adding extra property will not force the compiler to look for it. If you need to add a property after the creation, make the type of your variable any.

Property 'from' does not exist on type '{}' · Issue #41674 , Can I prevent the TypeScript compiler from caring about this? Error introduced by the following change: #41580. I tried using the @types/xxxx  TypeScript does syntactic transpilation, not functional polyfilling. That means if you use something like an arrow function, that is a syntactic feature of the language, therefore it is transpiled. TypeScript will not take care of things like Promise , Set , Map , WeakMap , etc. because those are functional aspects of the language.

In the given case, I would just rewrite it as

var object = {};

var withFirst =  {...object, get first() {return 37;}};

console.log('first property: ' + withFirst.first);

Typescript 2 Type System: How Does it Really Work? Type , A key thing about the Typescript Type System is that most of the times Error:(54​, 6) TS2339:Property 'name' does not exist on type '{}'. type is type {} , which means that user is an object with no properties, an empty object. When I compile with tsc I get the following "error": /home/bjarkef/sandbox/greeter.ts (8,53): The property 'value' does not exist on value of type 'HTMLElement'. However the compiler does output a javascript file, which works just fine in chrome.

TypeScript tutorial: Basics and typing in JavaScript, The method in Listing 3 always throws an error, so it does not terminate correctly. getAsync(arg: T): Promise { // ERROR: Property 'id' does not exist on type 'T' return Then you'll see following lines in on the console display: Greeter {}. greet​. Property 'scopes' does not exist on type 'IntrinsicAttributes & IntrinsicClassAttributes<Content> & Props & { children?: ReactNode; }'. Copy link Quote reply

error TS2339: Property 'X' does not exist on type '{}' : Angular2, What I believe is happening is typescript is infering type to be am empty object so your getting compile errors that x doesnt exist. When compiled/transpiled through TypeScript it generates error TS2339: Property 'myclassvar' does not exist on type 'MyClass'. If the above code snippet is valid ES6 then TypeScript should not generate the error. The generated javascript it valid. It's just that the error scares the developers trying to use ES6 without typings.

[Typescript] Property '' does not exist on type || Cannot find name , Hi! When I run my app for the first time with ionic cordova run browser -l, I get a lot of errors, but when I edit any file and save it, my app reloads  2339 Property 'style' does not exist on type 'Element'. If I change elem:Element to elem:HTMLElement then is says: 2345 Argument of type 'Element' is not assignable to parameter of type 'HTMLElement'. Property 'accessKey' is missing in type 'Element'.

Comments
  • Why would you need Object.defineProperty at all? Whydont just make it readonly ?
  • It works fine. But is this the propper way to do it? ps: first should be of type number in your interface
  • I think the line let object = {} as IFirst; will throw error cause the first property is required and missed in the type
  • Better to add an index signature [k: string]: any to the type instead of disabling all validation and all intellisense.