What is the advantage of initializing multiple javascript variables with the same var keyword?

by

There’s a slight advantage with the size of the javascript that is sent to the browser; Google’s Closure compiler in ‘whitespace only’ mode will compile the single var version into:

var x=some.initialization.method(),y=something.els(),z;

and the multi as:

var x=some.initialization.method();var y=something.els();var z;

I changed your else to els so that it would compile.

This isn’t a massive gain (especially if you are also compressing the files), and the ‘simple’ compilation mode will do this for you anyway, so I probably wouldn’t be too concerned about it unless you can find more compelling reasons.

One reason you may not want to do this is that if you accidentally use a semicolon instead of a comma you’ve just found a global.

More Related Contents:

  1. Find out how many tabs are opened in IE [closed]
  2. Create a Date with a set timezone without using a string representation
  3. CORS Error: “requests are only supported for protocol schemes: http…” etc
  4. Script tag in JavaScript string [duplicate]
  5. What is the difference between the mouseover and mouseenter events?
  6. React Context vs React Redux, when should I use each one? [closed]
  7. Headless Browser for Python (Javascript support REQUIRED!) [closed]
  8. MediaStream Capture Canvas and Audio Simultaneously
  9. add commas to a number in jQuery
  10. React Function Components with hooks vs Class Components
  11. Is there a template engine for Node.js? [closed]
  12. HTML table with fixed headers and a fixed column? [closed]
  13. Can I execute a function after setState is finished updating?
  14. How to use Cors anywhere to reverse proxy and add CORS headers
  15. How to prevent default on form submit?
  16. HTML Drag And Drop On Mobile Devices
  17. Event when input value is changed by JavaScript?
  18. JavaScript object destructuring and aliasing
  19. Alternative version for Object.values()
  20. Hide all elements with class using plain Javascript
  21. Append HTML to container element without innerHTML
  22. Why is a function declaration within a condition block hoisted to function scope in Chrome but not Firefox?
  23. How do I make a move up and down when I’m scrolling the page?
  24. Why doesn’t Node.js have a native DOM?
  25. How does the comma operator work in js? [duplicate]
  26. Transform Javascript Array into delimited String
  27. How to trigger the onclick event of a marker on a Google Maps V3?
  28. Cannot connect to MongoDB because of wrong URI
  29. Low power mode detection in JavaScript for iOS11?
  30. How to implement a Typescript interface to an es5-style “class”?

Leave a Comment