this — Class context
A class can be split into two contexts: static and instance.
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A class can be split into two contexts: static and instance. Constructors, methods, and instance field initializers (public or private) belong to the instance context. Static methods, static field initializers, and static initialization blocks belong to the static context. The this value is different in each context.
Class constructors are always called with new, so their behavior is the same as function constructors: the this value is the new instance being created. Class methods behave like methods in object literals — the this value is the object that the method was accessed on. If the method is not transferred to another object, this is generally an instance of the class.
Static methods are not properties of this. They are properties of the class itself. Therefore, they are generally accessed on the class, and this is the value of the class (or a subclass). Static initialization blocks are also evaluated with this set to the current class.
Field initializers are also evaluated in the context of the class. Instance fields are evaluated with this set to the instance being constructed. Static fields are evaluated with this set to the current class. This is why arrow functions in field initializers are bound to the instance for instance fields and to the class for static fields.
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MDN Web Docs — files/en-us/web/javascript/reference/operators/this/index.md :: Class context ↗Revision d14bee540b53 · CC-BY-SA-2.5 and attribution