[함수형 언어, 자바스크립트] 배열

control structure

자바스크립트에서 배열의 기본적인 활용은 다음과 같다. 

1. declaration 

//1. declaration
const arr1 = new Array();
const arr2 = [1, 2];

2. Looping

//2. Looping
const fruits = ["🍎", "🍌"];

  // a. for
  for(let i = 0; i < fruits.length(); i++){
      console.log(fruits[i]);
  }
  // b. for of
  for (let fruit of fruits) {
    console.log(fruit);
  }

  // c. forEach
  fruits.forEach((fruit, index) => console.log(fruit, index));

3. 추가, 삭제, 복사, 붙이기

// d. Addition, deletion, copy

// push
fruits.push("🍒", "🍑");
console.log(fruits);

// pop
fruits.pop();
console.log(fruits);

//shift: emove an item from the begining
fruits.shift();
console.log(fruits);

//unshitf: add on the item to the begining
fruits.unshift('🍉')

//splice: remove an item by index position
fruits.splice(1,1); // start and end pos
console.log(fruits)
fruits.splice(1,1,'🍏', '🍋')

// combine two arrays
const fruits2 = ['🍇', '🥑'];
const newFruits = fruits.concat(fruits2)
console.log(newFruits);

4. 탐색 

//5. Search
console.clear();
console.log(fruits);
console.log(fruits.indexOf('🍉'))

//includes
console.log(fruits.includes('🍏')); // true

//lastIndexof
fruits.push('🍏');
console.log(fruits);
console.log(fruits.indexOf('🍏'));
console.log(fruits.lastIndexOf('🍏'))

출처: YOUTUBE 드림코딩