13 JavaScript performance improvement tips to share_javascript tips

Daniel Clifford gave a great talk "Breaking the JavaScript Speed ​​Limit
with V8" at Google I/O 2012. In the speech, he explained in depth 13 simple code optimization methods that can make your code compile/run your JavaScript code faster in Chrome's V8 JavaScript engine. In his speech, he explained how to optimize and why. The key points of optimization are briefly listed below:

1. Initialize all objects in the constructor

2. Always initialize objects in the same order

3. Try to Use numbers

4. Use consecutive primary keys starting from 0 for the array

5. Do not allocate large arrays (>64K) in advance, you should expand the array as you use it

6. Do not delete elements in the array

7. Do not load uninitialized or deleted elements

8. For fixed-size arrays, use "array literals" to initialize

9. Allocate the correct space size to small arrays before use

10. Do not store non-numeric content in numeric arrays

11. Try to use a single type (monomorphic) Instead of polymorphic

12. Do not use try{} catch{}

13. Avoid modifying hidden classes in methods after optimization