homework/Функции 2/js/script.js

"use strict";

//TODO: ES6
// let a = msg => alert(msg);

// let cube = number => number * number * number;

// let avg2 = (a, b) => (a + b) / 2;

// let sum3 = (a = 0, b = 0, c = 0) => a + b + c;

// let intRandom = (a = 0, b = 0) => Math.round(Math.random() * (b - a)) + a;

// let greetAll = (...arguments) => {
//     for (let i in arguments) {
//         alert(arguments[i])
//     }
// }

// let sum = (...arguments) => {
//     let sumAll = 0
//     for (let i in arguments) {
//         sumAll += arguments[i]
//     }
//     return sumAll;
// }

function sort() {
    let persons = [{
            name: "Иван",
            age: 17
        },
        {
            name: "Мария",
            age: 35
        },
        {
            name: "Алексей",
            age: 73
        },
        {
            name: "Яков",
            age: 12
        },
    ]

    function sort(field, boolean = true) {
        if (boolean) {
            return (a, b) => a[field] > b[field] ? 1 : -1
        } else {
            return (a, b) => a[field] < b[field] ? 1 : -1
        }
    }

    console.log(persons.sort(sort('age', false)))
}
// sort()


function arrayMap() {
    let arr = ["1", {}, null, undefined, "500", 700];
    let newArr = arr.map(item => typeof (item) === "string" ? parseInt(item) : item);
    console.log(newArr)
}
// arrayMap()


function arrayReduce() {
    let arr = ['0', 5, 3, "string", null];

    let result = arr.reduce((sum, currentItem) => {
        if (typeof (currentItem) === "number") {
            sum *= currentItem;
        }
        return sum

    }, 1)
    console.log(result);
}
// arrayReduce()


function objectFilter() {
    let phone = {
        brand: "meizu",
        model: "m2",
        ram: 2,
        color: "black",
    };

    function filter(obj, func) {
        for (let key in obj) {
            console.log(func)
            if (!func(key, obj[key])) {
                delete obj[key]
            }
        }
    }

    filter(phone, (key, value) => key == "color" || value == 2);
    console.log(phone)
}
// objectFilter()

//OR

// let newObj = Object.entries(phone)
//     .filter(item => item[0] === "color" || item[0] === "ram")
//     .map(item => item);
// console.log(newObj)


function objectMap() {
    function map(object, callback) {
        let obj = {};
        for (let key in object) {
            Object.assign(obj, callback(key, object[key]));
        }
        return obj
    }

    let obj = map({
        name: "Иван",
        age: 17
    }, function (key, value) {
        let result = {};
        result[key + "_"] = value + "$";
        return result;
    })
    console.log(obj);
}
// objectMap()


function recursion() {
    let sum = (firstNumber, step, n) => {
        return n == 1 ? firstNumber : firstNumber + sum(firstNumber + step, step, n - 1);
    }
}
// recursion()

//TODO: HTML Tree (in process...)