Can you explain the distinction between a synchronous and asynchronous request in terms of their async parameter values (true/false)?

Can you explain the difference between setting async=false and async=true when utilizing the open method of the XMLHttpRequest?

function GetXML() {

    if (window.XMLHttpRequest) {// code for IE7+, Firefox, Chrome, Opera, Safari
        xmlhttp = new XMLHttpRequest();
    }
    else {// code for IE6, IE5
        xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
    }
    xmlhttp.onreadystatechange = test
    xmlhttp.open("GET", "PlanetCafe.xml", true);
    xmlhttp.send(null);
}

Answer №1

Check out this article on Mozilla Developer about Synchronous and Asynchronous Requests

XMLHttpRequest has the capability to handle both synchronous and asynchronous communications. But in general, it is recommended to use asynchronous requests over synchronous ones for better performance.

To elaborate, synchronous requests can block the code execution process and may lead to memory leaks and events issues, causing serious drawbacks. The only valid reason to opt for synchronous requests would be for easier downloads management within Web Workers.

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