Go 语言学习系列(三): 学习 handle an error

我们写代码肯定要做异常处理的. 所以本文介绍 Go 中如何做.

还是找到之前的 code, 粘贴下面的代码到 greetings.go 文件里面去:

package greetings

import (
	"errors"
	"fmt"
)

// Hello returns a greeting for the named person.
func Hello(name string) (string, error) {
	// If no name was given, return an error with a message.
	if name == "" {
		return "", errors.New("empty name")
	}

	// If a name was received, return a value that embeds the name
	// in a greeting message.
	message := fmt.Sprintf("Hi, %v. Welcome!", name)
	return message, nil
}

这段代码挺简单的,就不解析了.

然后得修改 hello.go 文件.

package main

import (
    "fmt"
    "log"

    "example.com/greetings"
)

func main() {
    // Set properties of the predefined Logger, including
    // the log entry prefix and a flag to disable printing
    // the time, source file, and line number.
    log.SetPrefix("greetings: ")
    log.SetFlags(0)

    // Request a greeting message.
    message, err := greetings.Hello("")
    // If an error was returned, print it to the console and
    // exit the program.
    if err != nil {
        log.Fatal(err)
    }

    // If no error was returned, print the returned message
    // to the console.
    fmt.Println(message)
}

这段代码也比较简单, 只不过是加入了 log, 在出错时输出一些 log 用于 debug.

运行结果如下:

异常处理今天学到这, 下一篇介绍 go 中的数组, Go slice.