Câu hỏi phỏng vấn Javascript
Câu hỏi

Why is extending built-in JavaScript objects not a good idea?

Câu trả lời

Extending built-in JavaScript objects, often referred to as "monkey patching," involves adding new functions or modifying existing ones in JavaScript's built-in prototypes, such as Object, Array, or String. While this practice can offer immediate functionality extensions, it is generally considered poor practice due to several significant drawbacks:

1. Maintainability and Readability Issues

Extending native objects can lead to code that is hard to understand and maintain. Future maintainers of the codebase might not be aware that built-in objects have been modified, leading to confusion and unexpected behaviors[1][2][3][6][7].

2. Collision and Compatibility Risks

If different parts of a codebase, or different dependencies, extend built-in objects in incompatible ways, it can lead to collisions. For example, if two libraries extend the Array.prototype but add a method with the same name that does different things, it can lead to unpredictable results[1][2][6][7]. Additionally, future versions of JavaScript might add new methods with the same names as your extensions, potentially breaking your code[7].

3. Performance Concerns

Modifying native prototypes can lead to performance issues. JavaScript engines optimize the execution of built-in methods extensively. Extending these objects can interfere with these optimizations, leading to slower code execution[1][2][3].

4. Prototype Pollution and Security Risks

Extending native prototypes can lead to prototype pollution, which can be a security risk in certain contexts. If properties are added to prototypes unsafely, it can lead to an avenue for attackers to manipulate these properties to their advantage[4].

5. Breaking Encapsulation

By extending a built-in prototype, you are effectively changing its behavior globally across your application. This breaks the encapsulation principle, where modifications should ideally be localized and not affect unrelated parts of an application[9].

6. Non-standard Behavior

Extensions to built-in prototypes do not form part of the JavaScript standard; thus, they can lead to behaviors that are not consistent across different JavaScript environments or runtime versions. This non-standard behavior can lead to issues when code is executed in different environments[1][2][6][7].

Alternatives to Exten...

middle

middle

Gợi ý câu hỏi phỏng vấn

senior

Check if a given string is a isomorphic

senior

What tools can be used to assure consistent code style?

middle

What are the differences between ES6 class and ES5 function constructors?

Bình luận

Chưa có bình luận nào

Chưa có bình luận nào