Javascript simple loop

Question

I saw the following code:

while(ajaxCallInProgress)
        {
        }
        ajaxCallInProgress = true;

What is the use of this empty loop in javascript? What is he doing? Thanks in advance...

Answer 1

if it ajaxCallInProgressis a true expression, it will be an infinite loop (and therefore, the interpreter will freeze forever).

In most cases, it makes sense to do something, while a specific condition is true, but in all these cases, the condition to be checked should at some point establish a false value inside the loop body.

Since ECMA- / Javascript does not support multiple threads (I just ignore web workers here), this variable cannot be changed anywhere else.

Conclusion

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Answer 2

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Answer 3

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Answer 4

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Answer 5

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, :

$. get ('url', {params: true}, () {  /* ajax */});

Answer 6

This code seems to be waiting for an ajax call to be answered. Basically, this loop waits until a global variable ajaxCallInProgressis set to falseanother JavaScript function.

So, when the answer is received, the corresponding JavaScript function will install ajaxCallInProgress = false;, and your loop will stop.

Answer 7

If "ajaxCallInProgress" is true at the beginning and the script does not run async, it would hang your browser.

If he starts async, it will consume a lot of CPU, but the browser will not hang .. it's hard to say anything else from this code.