I got the following snippet from this link: https://www.gkogan.co/blog/save-url-parameters/
<script>
var queryForm = function(settings){
var reset = settings && settings.reset ? settings.reset : false;
var self = window.location.toString();
var querystring = self.split("?");
if (querystring.length > 1) {
var pairs = querystring[1].split("&");
for (i in pairs) {
var keyval = pairs[i].split("=");
if (reset || sessionStorage.getItem(keyval[0]) === null) {
sessionStorage.setItem(keyval[0], decodeURIComponent(keyval[1]));
}
}
}
var hiddenFields = document.querySelectorAll("input[type=hidden], input[type=text]");
for (var i=0; i<hiddenFields.length; i++) {
var param = sessionStorage.getItem(hiddenFields[i].name);
if (param) document.getElementsByName(hiddenFields[i].name)[0].value = param;
}
}
setTimeout(function(){queryForm();}, 3000);
</script>
In short, this code is intended to get link parameters like utm_source and save it to the sessionStorage. What I don't understand is the following line that the tutorial doesn't explain:
var reset = settings && settings.reset ? settings.reset : false;
What does this syntax mean?