JSFiddle - React, Tailwind, and code Playground

JavaScript

var filenamesToProcessQueue = ['v.jpg','w.jpg','x.jpg','y.jpg','z.jpg']

function finishedProcessing (filename) {
console.log('finished processing: ' + filename)
// processing finished for this file, start again by chaining to the next one
doProcessFiles()
}

function waitForEachFile (filename, callback) {
// wait a couple of seconds and log the filename
setTimeout(function(){ console.log('Waited 2 seconds for: ' + filename);callback(filename);}, 2000)

}

function doProcessFiles() {
// get next file to process and remove it from the queue at same time
filename = filenamesToProcessQueue.pop()
// if the file is undefined then the queue was empty
if (typeof filename !== 'undefined') {
console.log('Process ' + filename)
waitForEachFile(filename, finishedProcessing)
}
}

doProcessFiles()