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JavaScript

Kelby Nylander
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Kelby Nylander
Full Stack JavaScript Techdegree Student 9,455 Points
Posted by Kelby Nylander
.a{fill-rule:evenodd;}techdegree
Kelby Nylander
Full Stack JavaScript Techdegree Student 9,455 Points

Example 2 of sync xhr.open('GET', url, false)?

I know it is an example of blocking code and not how we should code, but in the second example of the synchronous coding on like 3 it says xhr.open('GET', url, false); I am just starting to get comfortable with the basics of XMLHttpRequests but the 'false' is new to me. Can anyone explain? I was not able to gain much from just looking at the MDN page on the subject.

1 Answer

Jason Larson
Jason Larson
8,359 Points
Jason Larson
Jason Larson
8,359 Points

The false is for the optional value for making the request asynchronous. It is true by default, so that may be why you haven't seen it.

From the MDN page:

async Optional An optional Boolean parameter, defaulting to true, indicating whether or not to perform the operation asynchronously. If this value is false, the send() method does not return until the response is received. If true, notification of a completed transaction is provided using event listeners. This must be true if the multipart attribute is true, or an exception will be thrown.