I'm aware that "do-while" will run atleast once compared to "while" which has to satisfy a condition to run.
Is this correct usecase of do-while?
do{
var ajaxresponse = make an ajax call and assign the response to the variable.
while( ajaxresponse.length == <some number>);
For iterating and performing operations on response data, it's better to do that in callback function. Because AJAX is asynchronous. Following code uses Jquery for Ajax request.
$.ajax({
method: "POST",
url: "some.php",
data: { name: "John", location: "Boston" }
})
.done(function( ajaxresponse ) {
do{
//operations
}while(ajaxresponse.length == <some number> );
});
If you were to make the AJAX call synchronous, this would be valid.
ex.
$.ajax({url:"url",..., async: false});
BUT, this totally defeats the point of AJAX being asynchronous, so should be avoided.
No.
When JavaScript runs in a web client, it runs synchronously - meaning only one thread of execution for JavaScript is possible at a time.
Because of this, if a function makes a call for an asynchronous operation to be performed (like XmlHttpRequest.send or setTimeout), that operation is handled via a WebAPI by the browser OUTSIDE of the JavaScript runtime in a separate thread and the callbacks for that operation are then queued up and are executed when the JavaScript runtime is idle.
In your code:
do{
var ajaxresponse = make an ajax call and assign the response to the variable.
while( ajaxresponse.length == <some number>);
the ajaxresponse won't come back until the function containing the do/while loop completes, so when your while condition checks the ajaxresponse, there won't be a value to check.
do { await fetch(…); } while (…):-P