Exploring the differences between detecting the XMLHttpRequest object in JavaScript and using the try

When it comes to determining browser support for AJAX, I typically rely on object detection like this:

if (window.XMLHttpRequest) 
{ 
    xhr = new XMLHttpRequest();
} 
else if (window.ActiveXObject)
{
    xhr = new ActiveXObject("Microsoft.XMLHTTP");
}

However, more experienced developers often use a try-catch block instead:

try {
   xhr = new ActiveXObject("Microsoft.XMLHTTP");    //IE 
}
catch(e)    // if not IE
{
  xhr = new XMLHttpRequest(); 
}

There are differing opinions on whether try..catch is slower, but ultimately it seems to be a matter of personal preference. Is there a generally accepted approach or convention for handling this? I've encountered similar dilemmas in the past, such as choosing between innerHTML (not standard) and DOM (standard). Thank you for your insights and recommendations.

Answer №1

Consider trying this code snippet:

With this approach, the XMLHttpRequest is used first and if it fails, then ActiveXObject("Microsoft.XMLHTTP") is utilized as a fallback option. It's a more elegant and concise way to handle the situation.

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