What is a Property does not exist on type?

This TypeScript compile error (TS2339) is reported when you try to access a property that is not declared in the type of the variable. TypeScript enforces that every property access is known at compile time, so accessing an undeclared property is an error even if it might exist at runtime.

Why it happens

• •Accessing a property that was never added to the interface or type definition.
• •A typo in the property name that does not match any declared field.
• •Accessing a property on the result of an API call typed as a generic or base type that does not include that property.
• •A library was upgraded and a property was renamed or removed in the new version.

Examples

interface User {
  id: number;
  name: string;
}

const user: User = { id: 1, name: "Alice" };
console.log(user.email);

error TS2339: Property 'email' does not exist on type 'User'.

interface User {
  id: number;
  name: string;
  email?: string;  // add the property (optional)
}

const user: User = { id: 1, name: "Alice", email: "alice@example.com" };
console.log(user.email);

Related errors

• TypeError
• AttributeError