23 lines
434 B
Markdown
23 lines
434 B
Markdown
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```js run
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let user = {
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name: "John"
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};
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function wrap(target) {
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return new Proxy(target, {
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get(target, prop, receiver) {
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if (prop in target) {
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return Reflect.get(target, prop, receiver);
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} else {
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throw new ReferenceError(`Property doesn't exist: "${prop}"`)
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}
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}
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});
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}
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user = wrap(user);
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alert(user.name); // John
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alert(user.age); // ReferenceError: Property doesn't exist: "age"
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```
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