Get collection of label / value from form select element.

select-to-collection.js

// Pure JavaScript
function selectToCollection(selector, asJson) {
  var options = Array.from(document.querySelector(selector).querySelectorAll('option'));
	var collection = options.reduce((prev, curr) => {
		return [...prev, { label: curr.label, value: curr.value}];
	}, []);
    return (asJson === true) ? JSON.stringify(collection) : collection;
}


// With jQuery
function selectToCollection(selector, asJson) {
	var collection = $(selector).find('option').toArray().reduce((prev, curr) => {
		return [...prev, { label: curr.label, value: curr.value}];
	}, []);
    return (asJson === true) ? JSON.stringify(collection) : collection;
}