javascript
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Object Immortality: preventExtensions, seal, and freeze in JavaScript
Master the three levels of object locking in JavaScript to prevent unintended mutations and build robust applications.
2) Tech Review Report
Original Content Analysis
- Objective (TL;DR): Explains the differences between three APIs (preventExtensions, seal, freeze) that restrict object mutation with practical examples.
- Key Takeaways (Max 3)
- Technical Elements: Object.preventExtensions, Object.seal, Object.freeze, Array methods, Property descriptors, and try/catch.
Comparison of Object Lockdown Levels
In JavaScript, you can control the mutability of an object through three main methods, each providing a different level of protection.
Object.preventExtensions(): Prevents new properties from being added. Existing properties can still be deleted or modified.Object.seal(): Prevents adding or deleting properties. Existing properties can still have their value modified.Object.freeze(): The highest level of protection. Prevents adding, deleting, or modifying existing property values.
