Object Seal
Object Seal is a JavaScript concept that prevents adding or removing properties from an object, while allowing modification of existing property values. It is implemented through the Object.seal() method, which makes an object non-extensible and configurable attributes of all properties become false. This provides a level of immutability control in JavaScript, useful for creating more predictable and secure objects.
Developers should learn Object Seal when they need to enforce object structure in JavaScript applications, such as in configuration objects, API response handling, or state management to prevent accidental property additions or deletions. It is particularly valuable in large codebases or team environments where maintaining object integrity is crucial, and it serves as a middle ground between fully mutable objects and frozen objects (Object.freeze()).