[자바스크립트] Set 사용법

 

/* Create */
const set = new Set();

/* Add */
set.add(1)
set.add(2)
set.add(3)
set.add(1)
console.log(set) // Output: Set(3) { 1, 2, 3 }

/* Check */
console.log(set.has(1)) // true
console.log(set.has(5)) // false

/* Remove */
set.delete(1)

/* Size */
console.log(set.size) // 2

/* Iterate */
for (let item of set) {
  console.log(item)
}

set.forEach(value => {
  console.log(value)
})

/* Convert Set to Array */
const array = [...set]
const array2 = Array.from(set)

console.log(array)  // [2, 3]
console.log(array2) // [2, 3]

/* Use Cases */
const numbers = [1, 2, 2, 3, 4, 4];
const uniqueNumbers = [...new Set(numbers)];
console.log(uniqueNumbers); // [1, 2, 3, 4]