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 = 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>