JavaScript를 사용하여 비동기식 처리를 위한 다양한 방법

병렬 실행

class ApiClient {
  get(query: string) {
    return new Promise((resolve, _) => setTimeout(
      () => {
        console.log(`run: ${query} query`)
        resolve("ok")
      }
      , Math.random() * 1000)
    )
  }
}

const main = async () => {
  const client = new ApiClient()
  const queries = ['apple', 'banana', 'lemon', 'grape']

  // 並行に非同期処理を実効
  await Promise.all(queries.map(async (query) => client.get(query)))
}

main()

$ ts-node index.ts
run: grape query
run: banana query
run: lemon query
run: apple query

순차적으로 집행하다

class ApiClient {
  get(query: string) {
    return new Promise((resolve, _) => setTimeout(
      () => {
        console.log(`run: ${query} query`)
        resolve("ok")
      }
      , Math.random() * 1000)
    )
  }
}

const main = async () => {
  const client = new ApiClient()
  const queries = ['apple', 'banana', 'lemon', 'grape']

  // 直列に非同期処理を実効
  for(const query of queries) {
    await client.get(query)
  }
}

main()

$ ts-node index.ts
run: apple query
run: banana query
run: lemon query
run: grape query