// switch: sizes

let size = prompt("Enter your ukrainian size");
switch (size){
case "40": document.write("<div>American size - 6</div>");
                break;
case "42": document.write("<div>American size - 8</div>");
                break;
case "44": document.write("<div>American size - 10</div>");
                break;
case "46": document.write("<div>American size - 12</div>");
                break;
case "48": document.write("<div>American size - 14</div>");
                break;
case "": document.write("<div>Size not specified</div>");
                break;
        default: document.write("<div>Not a size</div>");
    }

// switch: if

    let color = prompt("Введите цвет");
         if (color === "red") 
{document.write("<div style='background-color: red;'>red</div>")}
 else if (color === "black")
{document.write("<div style='background-color: black; color: white;'>black</div>")}
    else if (color === "blue") 
{document.write("<div style='background-color: blue; color: white;'>blue</div>")}
    else if (color === "green") 
{document.write("<div style='background-color: green; color: green ;'>green</div>")} else {document.write("<div style='background-color: gray;'>Not a color</div>")}
 

// prompt: or(?)

let age = prompt('сколько вам лет?');
if (age === '' || age === null){
alert('Error')}
else {
bornYear = 2022 - age;
alert(`Вы ${bornYear} года`)
}

            
// confirm: or this days

let qvest0 = confirm('Shoping?');
alert( false || "ты бяка");

// confirm: if this days

let qvest = confirm('Shoping?');
if (qvest === false){
alert('Ты бяка')}

//  triple prompt

let name = prompt('Enter your name');
let surname = prompt('Enter your surname');
let middleName = prompt('Enter your middle name')
alert(name + ' ' + surname + ' ' + middleName);

//  default: or 

let defName = "Marko";
let defSurname = "Volchenko";
let defMiddleName = "Alexandrovich";
let name1 = prompt("Enter your name") || defName;
let surname1 = prompt("Enter your surname") || defSurname ;
let middleName1 = prompt("Enter your middle name ") || defMiddleName;
alert(name1 + " " + surname1 + " " + middleName1);
        

// default: if 

let defName1 = 'Marko'
let defSurname1 = 'Volchenko'
let defMiddleName1 = 'Alexandrovich';
let name2 = prompt("Enter your name")
if (name2 === null || name2 === "") {
name2 =  defName1} else {name2};
let surname2 = prompt("Enter your surname")
if (surname2 === null || surname2 === "") {
surname2 =  defSurname1} else {surname2};
let middleName2 = prompt("Enter your middlename")
if (middleName2 === null || middleName2 === "") {
middleName2 =  defMiddleName1} else {middleName2};
alert( name2 + ' ' + surname2 + ' ' + middleName2);
        
// login and password

let login = prompt('Enter your login');
if (login === 'admin'){alert('Great!')}
else {alert('Error')}
let pass = prompt('Enter your password');
if (pass === 'qwerty'){alert("Great!")}
else{alert('Error')};


                
// currency calc

let currency = prompt("usd or eur?");
let course;
switch(currency){
case 'usd':course = 36.65;
break
case 'eur':course = 37.95;
break
}
let uah = prompt('How much hrivna?');
let result = Math.floor(uah/course);
alert(`You have ${result} currency`);

// currency calc: improveds


let currency0 = prompt("usd or eur?");
let course0;
switch(currency0.toLowerCase()){
case 'usd':course0 = 36.65;
break
case 'eur':course0 = 37.95;
break
}
let uah0 = prompt('How much hrivna?');
let result0 = Math.floor(uah0/course0);
alert(`You have ${result0} currency`);



// currency calc: two rates

                        
let currency1 = prompt("usd or eur?");
let currency2 = prompt('buy or sell?')
let course1;
let course2;
switch(currency1 && currency2 )  {
case 'usd' && 'sell':course1 = 37.03;
    break
case 'eur' && 'sell':course1 = 37.87;
    break
case 'usd' && 'buy':course2 = 36.65;
    break
case 'eur' && 'buy':course2 = 37     
}
let uah1 = prompt('How much hrivna?');
let result1 = Math.floor(uah1/course1 || uah1/course2);
alert(`You have ${result1} currency`);

                        
// currency calc: if
                       
                        
let currency3 = prompt("usd or eur?");
let currency4 = prompt('buy or sell?')
let uah2 = prompt('How much hrivna?')
if (currency3 == 'usd' && currency4 =='sell'){
    alert(`You have ${Math.floor(uah2/37.03)} $`)
}else if (currency3 = 'eur' && currency4 == 'sell'){
    alert(`You have ${Math.floor(uah2/37.87)} €`)
}else if (currency3 == 'usd' && currency4 =='buy'){
    alert(`You have ${Math.floor(uah2/36.65)} $`)}
    else if (currency3 = 'eur' && currency4 == 'buy'){
        alert(`You have ${Math.floor(uah2/37.47)} €`)}else;
                            
                       
                       
                       
// scissors

let myChoice = +prompt ('Enter your number 1-3: 1 - stone, 2 - scissors, 3 - paper')
let compChoice = Math.ceil(Math.random()*3);
   alert(`Computer choice - ${compChoice}`);
 if (myChoice === 1 && compChoice === 2 || myChoice === 2 && compChoice === 3 || myChoice === 3 && compChoice === 1 ){
alert('You win!')
} else if (myChoice === 1 && compChoice === 3 || myChoice === 2 && compChoice === 1 || myChoice === 3 && compChoice === 2 ){
alert('You lose!')} else 
 {
 alert('Friendship!!!')
  }