HW-1-6/hw-3.js

// *************1*************
var person = [
    a = {surname: 'A', name: 'aa', fathername: 'Aa', country: 'Ukraine',},
    b = {surname: 'B', name: 'bb', country: 'Polsha',},
    c = {surname: 'C', name: 'cc', country: 'Vengria',}
];

// *************2*************
for (var items of person) {
    console.log(items);
}
// *************3*************
for (var i = 0; i < person.length; i++) {
    console.log('name: ' + person[i].name);
    console.log('surname: ' + person[i].surname);
}
// *************4*************
for (var i = 0; i < person.length; i++) {
    if ('fathername' in person[i]) {
        person[i].fullName = prompt('enter full name',)
    }
}
console.log(person);
// *************5*************
let json = JSON.stringify(person);
console.log(json);
// *************6*************
let d = '{"surname":"D","name":"dd"}';
d = JSON.parse(d);
person.push(d);
console.log(person);
// *************7*************
var str = "<table border='1'><tr><td>Name</td><td>Surname</td></tr>";
for (let i = 0; i < person.length; i++) {
    str += ' <tr><td>${person[i].name}</td><td>${person[i].surname}</td></tr>'
}
str += "</table>";
console.log(str);
document.write(str);

// *************8*************
function avg2(a, b) {
    if (isNaN(a) || isNaN(b)) {
        console.log('there must be numbers');
    }
    else {
        return ((a + b) / 2);
    }
}

console.log(avg2(4, 6));

// *************9*************
function sum(a, b, c) {
    if (isNaN(a)) {
        return b + c
    }
    if (isNaN(b)) {
        return a + c
    }
    else if (isNaN(c)) {
        return a + b
    }
    else if (isNaN(b) && isNaN(c) && isNaN(a)) {
        return 'error';
    }
    else return a + b + c;
}

console.log(sum(1, 'fdrhzrht', 5));

// *************10*************
function intRandom(a, b) {
    if (b === undefined) {
        b = a;
        a = 0;
    }
    a = Math.ceil(a);
    b = Math.floor(b);
    return Math.round(Math.random() * (b - a + 1)) + a;
}

console.log(intRandom(5));

// *************11*************
function sum(...arguments) // параметры собираются в массив params
{
    var sum = 0;
    for (let i = 0; i < arguments.length; i++) {
        sum += arguments[i];
    }
    return sum;
}

console.log(sum(3, 45, 7, 3, 4, 5, 6, 7));