Алексей

let initToIndex = arr1.reduce((acc, item, idx) => {
	acc[item[0].init] = idx;
	return acc;
}, {});

arr2.flat().forEach(x => {
	let idx = initToIndex[x.init];
	if (!initToIndex.hasOwnProperty(x.init)) {
		idx = arr1.push([]) - 1;
		initToIndex[x.init] = idx;
	};
	
	arr1[idx].push(x);
	
});

document.querySelector('.select__language').value = window.location.pathname.split('/').pop();

window.addEventListener("hashchange", (e) => {

	document.querySelectorAll('.lang > a').forEach(el = el.classList.remove('active'));
	
	switch(location.hash) {
		case '#en': document.getElementById('lang-en').classList.add('active'); break;
		case '#fr': document.getElementById('lang-fr').classList.add('active'); break;
		default: break;
	};
	
}, false);

date = dataObj.pickup_date.toString().split('/').reverse().join('-');

let ALERTDEBOUNCER;
window.addEventListener('mousemove', e => {
	clearTimeout(ALERTDEBOUNCER);
	ALERTDEBOUNCER = setTimeout(() => {
		console.log('I think user is dead');
	}, 3000);
});

var word = ['ноль','один','два','три','четыре','пять','шесть','семь','восемь','девять'];
function lastdigit() {
	var n = prompt('Enter number ', 27).split('').pop();
	alert("last digit = " + word[n ?? 0]);
};
lastdigit();