illiaKozyr
/
Homework


			
				
					
						
						
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							<!DOCTYPE html>
<html lang="en">
	<head>
		<meta charset="UTF-8" />
		<meta http-equiv="X-UA-Compatible" content="IE=edge" />
		<meta name="viewport" content="width=device-width, initial-scale=1.0" />
		<title>Document</title>
	</head>
	<body>
		<script>
			// -----------------------sort

			var persons = [
				{ name: "Иван", age: 17 },
				{ name: "Мария", age: 35 },
				{ name: "Алексей", age: 73 },
				{ name: "Яков", age: 12 },
			];

			function sort(array, objectKey, boolean) {
				if (boolean) {
					array.sort((a, b) =>
						a[objectKey] < b[objectKey] ? 1 : -1
					);
				} else {
					array.sort((a, b) =>
						a[objectKey] > b[objectKey] ? 1 : -1
					);
				}
			}

			// sort(persons, "age")
			sort(persons, "name", false);

			// ------------------------array map

			var array = ["1", {}, null, undefined, "500", 700];

			// array.map( a => (a === Number ? +a : a))

			let b = array.map((a) => {
				let number = Number(a);
				return isNaN(a) ? a : number;
			});
			console.log(b);

			// ------------------------array reduce

			var array2 = ["0", 5, 3, "string", null];
			let productNumber = array2.reduce(function (a, b) {
				if (typeof b === "number") {
					a *= b;
				}
				return a;
			}, 1);
			console.log(productNumber);

			// ------------------------object filter

			var phone = {
				brand: "meizu",
				model: "m2",
				ram: 2,
				color: "black",
			};

			function filter(obj, callback) {
				let newObj = {};
				for (let key in obj) {
					if (callback(key, obj[key])) {
						newObj = { ...newObj, [key]: obj[key] };
					}
				}
				return newObj;
			}

			filter(phone, (key, value) => key === "color" || value === 2);

			//-----------------------object map

			function map(obj, callBack) {
				let result = {};
				for (let key in obj) {
					result = { ...result, ...callBack(key, obj[key]) };
					return result;
				}
			}

			map({ name: "Иван", age: 17 }, function (key, value) {
				var result = {};
				result[key + "_"] = value + "$";
				return result;
			}); //должен вернуть {name_: "Иван$", age_: "17$"}

			//-----------------------Рекурсия

			function progression_sum(max_num_in_progressian) {
				if (max_num_in_progressian === 1) return 1;

				console.log(max_num_in_progressian);
				let result =
					progression_sum(max_num_in_progressian - 1) +
					max_num_in_progressian;
				console.log(max_num_in_progressian, result);

				return result;
			}

			console.log(progression_sum(5));
		</script>
	</body>
</html>