javascript / intermediate
Snippet
Intercepting Operations with Proxy
The Proxy object allows you to create a wrapper for another object to intercept and redefine fundamental operations like property access, assignment, and enumeration.
snippet.js
javascript
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const user = { name: 'Alice' };const proxy = new Proxy(user, {get: (target, prop) => prop in target ? target[prop] : 'Property not found',set: (target, prop, value) => {if (prop === 'age' && value < 0) throw new Error('Invalid age');target[prop] = value;return true;}});
Breakdown
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get: (target, prop) => prop in target ? target[prop] : 'Property not found',
Defines a 'trap' for reading properties, providing a fallback value if the key doesn't exist.
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set: (target, prop, value) => { ... }
Defines a 'trap' for writing properties, enabling validation logic before the update occurs.