const color = ['🟡','🟣','🟢'];
color.unshift('🔴'); // unshift
console.log(color); // ['🔴', '🟡','🟣','🟢']
let first = color.shift(''); // shift
console.log(color, first); // ['🟡','🟣','🟢'], '🔴'
color.push('🔵'); // push
console.log(color); // ['🟡','🟣','🟢','🔵']
let last = color.pop(''); // pop
console.log(color, first); // ['🟡','🟣','🟢'], '🔵'
배열.join(구분문자);
const heart = ['💛', '💚', '💙'];
let joinHeart01 = heart.join();
console.log(joinHeart01); // 💛,💚,💙
let joinHeart02 = heart.join('');
console.log(joinHeart02); // 💛💚💙
let joinHeart03 = heart.join('&');
console.log(joinHeart03); // 💛&💚&💙
주로 이런 식으로 사용된다.
const phone = ['010', '1111', '2222'];
const phoneJoin = numbers.join('-');
console.log(phoneJoin); // 010-1111-2222
문자열.split(구분문자);
const phoneSplit01 = '010-1111-2222'.split();
console.log(phoneSplit01); // ['010-1111-2222']
const phoneSplit02 = '010-1111-2222'.split('');
console.log(phoneSplit02); // ['0', '1', '0', '-', '1', '1', '1', '1', '-', '2', '2', '2', '2']
const phoneSplit03 = '010-1111-2222'.split('-');
console.log(phoneSplit03); // ['010', '1111', '2222']
배열.fill(value);
배열.fill(value, startNum, endNum);
const fiveApple = Array(5).fill('🍎');
console.log(fiveApple); // ['🍎','🍎','🍎','🍎','🍎'];
fiveApple.fill('🍋', 1, 4);
console.log(fiveApple); // ['🍎', '🍋', '🍋', '🍋', '🍎']
fiveApple.fill('🍇', -3);
console.log(fiveApple); //['🍎', '🍋', '🍇', '🍇', '🍇']
const blues = ['💙','🔵','🟦','🔷','🔵'];
const findCircle = blues.find((figure) => figure ==='🔵');
console.log(findCircle); // 🔵
배열에서 맨 처음으로 조건에 해당하는 값의 인덱스(위치)를 찾아낸다.
const blues = ['💙','🔵','🟦','🔷','🔵'];
const findIndexCircle = blues.findIndex((figure) => figure ==='🔵');
console.log(findIndexCircle); // 1
const blues = ['💙','🔵','🟦','🔷','🔵'];
const findCircles = blues.filter((figure) => figure ==='🔵');
console.log(findCircles); // ['🔵', '🔵']
배열.indexOf(value)
배열.indexOf(value, fromIndex)
const setMenu =['🍟','🍔','🥤','🍗','🍔'];
const indexOfburger01 = setMenu.indexOf('🍔');
console.log(indexOfburger01); // 1
const indexOfburger02 = setMenu.indexOf('🍔', 3);
console.log(indexOfburger02); // 4
const indexOfPizza = setMenu.indexOf('🍕');
console.log(indexOfPizza); //-1
배열.includes(value)
배열.includes(value, fromIndex)
const setMenu =['🍟','🍔','🥤','🍗','🍔'];
const includesDrink01 = setMenu.includes('🥤');
console.log(includesDrink01); //true
const includesDrink02 = setMenu.includes('🥤', -3);
console.log(includesDrink02); //true
const includesDrink03 = setMenu.includes('🥤', 3);
console.log(includesDrink03); //false
const includesRice = setMenu.includes('🍙');
console.log(includesRice); //false
const lionFE2 = Array(70).fill('🦁');
console.log(lionFE2);
lionFE2.unshift('🦄');
lionFE2.push('🦄');
console.log(lionFE2);
lionFE2.shift();
lionFE2.pop();
console.log(lionFE2);
const noLionFE2 = ['🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦄', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦄', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁', '🦁'];
noLionFE2.includes('🦄');
noLionFE2.indexOf('🦄');
noLionFE2.indexOf('🦄',22);
noLionFE2.find((lion) => lion !=='🦁');
noLionFE2.findIndex((lion) => lion !=='🦁');
noLionFE2.filter((lion) => lion !=='🦁');
const lionFE2 = noLionFE2.filter((lion) => lion ==='🦁');
🦁❤