ProgressEvent.loaded read-only property is an integer
representing the amount of work already performed by the underlying process. The ratio
of work done can be calculated with the property and
When downloading a resource using HTTP, this only represent the part of the content
itself, not headers and other overhead.
value = ProgressEvent.loaded
|XMLHttpRequest Standard (XMLHttpRequest)|
BCD tables only load in the browser
ProgressEventinterface it belongs to.