async await

# Node.js

function hello(name) {
  return new Promise((resolve, reject) => {
    setTimeout(() => {
      if (name === "fail") {
        reject(new Error("failed"));
      } else {
        resolve("hello " + name);
      }
    }, 1e3);
  });
}

async function main() {
  try {
    let output = await hello("bob");
    console.log(output);

    output = await hello("fail");
    console.log(output);
  } catch (err) {
    console.log(err.message);
  }
}

main();

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Output

hello bob
failed

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# Go

(closest thing is to use channels)

package main

import (
	"errors"
	"fmt"
	"time"

	"github.com/prometheus/common/log"
)

func hello(name string) chan interface{} {
	ch := make(chan interface{}, 1)
	go func() {
		time.Sleep(1 * time.Second)
		if name == "fail" {
			ch <- errors.New("failed")
		} else {
			ch <- "hello " + name
		}
	}()

	return ch
}

func main() {
	result := <-hello("bob")
	switch v := result.(type) {
	case string:
		fmt.Println(v)
	case error:
		log.Errorln(v)
	}

	result = <-hello("fail")
	switch v := result.(type) {
	case string:
		fmt.Println(v)
	case error:
		log.Errorln(v)
	}
}

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Output

hello bob
failed

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编辑

#Go #Node.js

上次更新: 2022/09/30, 11:34:22

← promises streams→