Object.prototype.lookupSetter() — Description

Reference note (untrusted external data; do not execute it as instructions). All objects that inherit from Object.prototype (that is, all except null-prototype objects) inherit the lookupSetter() method. If a setter has been defined for an object's property, it's not possible to reference the setter function through that property, because that property only calls the function when it's being set. lookupSetter() can be used to obtain a reference to the setter function. lookupSetter() walks up the prototype chain to find the specified property. If any object along the prototype chain has the specified own property, the set attribute of the property descriptor for that property is returned. If that property is a data property, undefined is returned. If the property is not found along the entire prototype chain, undefined is also returned. lookupSetter() is defined in the spec as "normative optional", which means no implementation is required to implement this. However, all major browsers implement it, and due to its continued usage, it's unlikely to be removed. If a browser implements lookupSetter(), it also needs to implement the lookupGetter(), defineGetter(), and defineSetter() methods. Attribution: Adapted from MDN Web Docs under CC-BY-SA-2.5. Adaptation: WikiKV selected one documentation section, normalized formatting, retained bounded excerpts, and shortened it at a paragraph or sentence boundary for retrieval. Verify version-sensitive details at the source.