Иван Соломенников

let arr = [1, 2, 3, 4, 5, 6, 7, 8];

arr.reduce((tmp, elt, index) => {
	return arr[index] = tmp + elt;
});

console.log(arr); // [1, 3, 6, 10, 15, 21, 28, 36]

const elts = document.querySelectorAll("ul#list li");
let sum = 0;

elts.forEach(elt => {
	sum += Number(elt.innerHTML.split('-')[1]);
});

public void toLeft(String[][] arr) {
		
		String tmp;
	
		for(int i = 0, outLen = arr.length; i < outLen; i++) {
			
			for(int j = 0, inLen = arr[i].length; j < inLen; j++) {
				
				if((j + 1) < inLen) {

					tmp = arr[i][j];
					arr[i][j] = arr[i][j+1];
					arr[i][j+1] = tmp;

				} else
				    arr[i][j] = "0";
			}
		}
	}

String[][] arr =  {
					{"2020", "2019", "2018"},
					{"4", "5", "6"},
					{"777", "87", "999"},
				};

toLeft(arr);

for(int i = 0, outLen = arr.length; i < outLen; i++) {
	
	for(int j = 0, inLen = arr[i].length; j < inLen; j++)
		System.out.format("%s ", arr[i][j]);
}

// Результат это примера будет такой: 2019 2018 0 5 6 0 87 999 0

function moveToStart(arr, n) {

	if(n && n < arr.length) {

		while(n--)
			arr.unshift(arr.pop());
	}

	return arr;
}

console.log(moveToStart([1, 2, 3, 4, 5], 3)); // [3, 4, 5, 1, 2]

function moveToStart(arr, n) {

	const amount = arr.length - n;

	return arr.slice(amount).concat(arr.slice(0, amount));
}

console.log(moveToStart([1, 2, 3, 4, 5], 3)); // [3, 4, 5, 1, 2]

console.log('sto '.indexOf('sto ')); // 0 - true

console.log('sto re '.indexOf('sto ')); // 0 - true

const r = (0.1 + 0.2);

console.log(r.toFixed(1)); // 0.3

a.header__lang-link_ru:hover {
    text-decoration: underline;
}

a.header__lang-link_en:hover {
    text-decoration: underline;
}