zulbukharov / learn_js

ARRAY

declare array

let todoList = [];

function rememberTo(task) {
	todoList.push(task);
}

function whatIsNext() {
	return todoList.shift();
}

function urgentlyRememberTo(task) {
	todoList.unshift(task);
}

console.log([1, 2, 3, 2, 1].indexOf(2));
// → 1

console.log([1, 2, 3, 2, 1].lastIndexOf(2));
// → 3

console.log([0, 1, 2, 3, 4].slice(2, 4));
// → [2, 3]

console.log([0, 1, 2, 3, 4].slice(2));
// → [2, 3, 4]

add elements in slice

console.log(["hello", "bro"].join(" "));
// -> hello bro

[1].concat([2])
// [1, 2]

STRINGS

strings are constants

console.log("раз два три".indexOf("ва"));
// -> 5 

console.log(" ладно \n ".trim());
// → ладно