How test if a particular line of JavaScript code is supported by Browser

Question

Could anybody suggest how can I test if a particular line of JavaScript code is supported by Browser or not. If not how can I handle it? As I am learning JavaScript it would be a great help to know.

Please post the specific code you're asking about. The techniques vary depending upon what it is. — jfriend00
– jfriend00, Commented Nov 13, 2014 at 1:24
There's a site I ran across a few weeks ago where you paste in JS and it detects potential browse compatibility issues, but I'm too lazy to track it down right now. I tried it and it seemed to be moderately useful. — user663031
– user663031, Commented Nov 13, 2014 at 1:36
More context information is needed. Do you want to take any arbitrary line of JS code and find out whether it can be executed in the browser? I.g. i++ or new Map()? Or do you want to conditionally execute code in your own module? — Felix Kling
– Felix Kling, Commented Nov 13, 2014 at 1:39

David Thomas · Accepted Answer · 2014-11-13 01:28:25Z

3

This would seem to be the perfect time to use try/catch:

    try {
        // your JavaScript here
        document.executeSomeUnknownFunction();
    }
    catch (error) {
        console.log("There was an error: " + error);
    }

console.log("...but nothing broke");

Or, alternatively, assuming it's a method of an Object you're testing for (for example querySelectorAll()):

if ('querySelectorAll' in document) {
  console.log("We support  'document.querySelectorAll()'");
 }

References:

edited Nov 13, 2014 at 1:28

answered Nov 13, 2014 at 1:22

David Thomas

254k53 gold badges382 silver badges421 bronze badges

Sign up to request clarification or add additional context in comments.

6 Comments

Thilo Over a year ago

Might be that something does not work, but there is no exception.

David Thomas Over a year ago

True, but it depends what 'that' might be; and given the limited information in the question it's hard to account for possibilities I can't anticipate.

Thilo Over a year ago

That's right. This question can most likely not be answered in a general way. Like @jfriend00 said in the comments: The techniques vary depending upon what it is.

Thilo Over a year ago

BTW: console.log might also not supported ;-)

David Thomas Over a year ago

@Thilo: that would be entertainingly ironic... :D

|

JCOC611 · Accepted Answer · 2014-11-13 01:23:08Z

2

You can either: 1) Assume that the code works, and handle the cases where it doesn't:

try{
   // ...
}catch(e){
   // an error occurred
}

Or 2) check if the function it relies on exists, and then use it:

if(window.yourfunction){
   // The function is present in the global scope
}else{
   // Not available, try alternatives?
}

answered Nov 13, 2014 at 1:23

JCOC611

19.8k15 gold badges71 silver badges90 bronze badges

Collectives™ on Stack Overflow

How test if a particular line of JavaScript code is supported by Browser

2 Answers 2

6 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

6 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related