Javascript問題集（繰り返し）解答
「Javascript問題集（繰り返し）」の解答は下記になります。
問題１の解答
let foods = ["Pizza", "Curry", "Steak", "Seafood Paella", "Spaghetti Bolognese"];
for (let i = 0; i < foods.length; i++) {
console.log(foods[i]);
}
問題２の解答
for (let i = 0; i <= 10; i++) {
console.log(2 ** i);
}
問題３の解答
for (let i = 3; i <= 15; i += 3) {
console.log(i);
}
問題４の解答
for (let i = 2 i <= 10; i += 2) {
console.log(i);
}
問題５の解答
let book = {name: "delicious food", pageVolume: 102, price: 1580};
for (let key in book) {
if (book.hasOwnProperty(key)) {
console.log(key + ": " + book[key]);
}
}
問題６の解答
let product = {name: "cream", weight: 30, price: 1280};
for (let key in product) {
console.log(key + ": " + product[key]);
}
問題７の解答
for (let i = 1; i <= 5; i++) {
console.log(i);
}
問題８の解答
let buildings = ["Sydney Opera House", "Taj Mahal", "Statue of Liberty", "Leaning Tower of Pisa"];
for (let building of buildings) {
console.log(building);
}
問題９の解答
let numbers = [33, 78, 21, 37, 52, 32]; let sum = numbers.reduce((acc, cur) => acc + cur); console.log(sum);
問題１０の解答
let countries = ["Spain", "Canada", "Germany", "Australia", "Japan"];
for (let i = 0; i < countries.length; i++) {
console.log(countries[i].length);
}
問題１１の解答
let numbers = [1, 2, 3, 4, 5];
let sum = 0;
for (let i = 0; i < numbers.length; i++) {
sum += numbers[i];
}
console.log(sum);
問題１２の解答
let numbers = [1, 3, 6, 2, 3, 8, 1, 5, 8, 2, 1];
let uniqueNumbers = [];
for (let number of numbers) {
if (!uniqueNumbers.includes(number)) {
uniqueNumbers.push(number);
}
}
console.log(uniqueNumbers);
問題１３の解答
const array = ["car", "bus", "ship", "plain", "train"];
for (let i = 0; i < array.length; i++) {
console.log(array[i]);
}
問題１４の解答
let sum = 0;
let i = 1;
while (i <= 1000) {
if (i % 3 === 0) {
sum += i;
}
i++;
}
console.log(sum);
問題１５の解答
「for...in」はオブジェクトに対して利用するが、「for...of」は配列に対して利用する。
(例)
■for...in
let shop = {
name: 'relax ship',
phone:'111-xxx-2222',
prefecture: 'Tokyo'
}
for( let data in shop){
console.log(data); //keyが表示される
console.log(shop[data]); //valueが表示される
}
(例)
■for...of
let numbers = [22, 12, 56, 32, 78];
for (let number of numbers) {
console.log(number);
}
問題１６の解答
let numbers = [23, 25, 32, 54, 12 ,23, 76 ,87, 35];
let max = numbers[0];
for (let i = 1; i < numbers.length; i++) {
if (numbers[i] > max) {
max = numbers[i];
}
}
console.log(max);
問題１７の解答
for (let i = 10; i >= 1; i--) {
console.log(i);
}
問題１８の解答
let sum = 0;
let num;
do {
num = parseInt(prompt("数値を入力してください（処理終了するには「0」を入力してください。）"));
sum += num;
} while (num !== 0);
console.log(sum);
問題１９の解答
const str = "Programming";
for (let i = 0; i < str.length; i++) {
console.log(str[i]);
}
問題２０の解答
const array = ["apple", "banana", "cherry"];
for (let i = 0; i < array.length; i++) {
console.log(array[i]);
}