Golang中多个if代码优化小技巧
作者：yunyi
这篇文章主要为大家详细介绍了Golang中一些常用的if代码优化小技巧,w文中的示例代码简洁易懂,具有一定的借鉴价值,感兴趣的小伙伴可以跟随小编一起学习一下
没优化之前: 嵌套if, 检查是否有中文字段值, 否则去查找英文值, 都没有则返回默认值
if record.City.Names["zh-CN"] == "" {
city = record.City.Names["en"]
if record.City.Names["en"] == "" {
city = record.City.Names["en"]
}
} else {
city = "未知地域"
}优化后: 平级if...else代替嵌套if
if name, ok := record.City.Names["zh-CN"]; ok {
city = name
} else if city, ok = record.City.Names["en"]; ok {
city = record.City.Names["en"]
} else {
city = "未知地域"
}知识点: 利用go的ok模式,对查询map对象的值是否存在更加简洁和安全
更进一步的优化, 去掉else
这对else的处理逻辑有明确的值时非常有用
city = "未知地域"
if name, ok := record.City.Names["zh-CN"]; ok {
city = name
} else if name, ok = record.City.Names["en"]; ok {
city = name
}使用switch代替多个if分支: 根据成绩的分数段给出对应的等级
func calculateGrade(score int) string {
var grade string
if score >= 90 && score <= 100 {
grade = "A"
} else if score >= 80 && score < 90 {
grade = "B"
} else if score >= 70 && score < 80 {
grade = "C"
} else if score >= 60 && score < 70 {
grade = "D"
} else if score >= 0 && score < 60 {
grade = "F"
} else {
grade = "Invalid Score"
}
return grade
}优化后: 使代码更加简洁，并且避免了多个嵌套的 if-else 语句。同时，使用 switch 语句还能够处理默认情况，即当 score 不满足任何一个分支条件时，默认返回 "Invalid Score"
func calculateGrade(score int) string {
var grade string
switch {
case score >= 90 && score <= 100:
grade = "A"
case score >= 80 && score < 90:
grade = "B"
case score >= 70 && score < 80:
grade = "C"
case score >= 60 && score < 70:
grade = "D"
case score >= 0 && score < 60:
grade = "F"
default:
grade = "Invalid Score"
}
return grade
}错误检查
首先看etcdgithub官网的错误处理例子:
resp, err := cli.Put(ctx, "", "")
if err != nil {
switch err {
case context.Canceled:
log.Fatalf("ctx is canceled by another routine: %v", err)
case context.DeadlineExceeded:
log.Fatalf("ctx is attached with a deadline is exceeded: %v", err)
case rpctypes.ErrEmptyKey:
log.Fatalf("client-side error: %v", err)
default:
log.Fatalf("bad cluster endpoints, which are not etcd servers: %v", err)
}
}我们可以进一步优化, 使用go自带的包errors对错误类型进行更加健壮的检查, 但是对开发者的要求较高, 需要预定义正确的错误类型, 来保证正确的比较错误
resp, err := cli.Put(ctx, "", "")
if err2 != nil {
switch {
case errors.Is(err, context.Canceled):
log.Fatalf("ctx is canceled by another routine: %v", err)
case errors.Is(err, context.DeadlineExceeded):
log.Fatalf("ctx is attached with a deadline is exceeded: %v", err)
case errors.Is(err, rpctypes.ErrEmptyKey):
log.Fatalf("client-side error: %v", err)
default:
log.Fatalf("bad cluster endpoints, which are not etcd servers: %v", err)
}
}到此这篇关于Golang中多个if代码优化小技巧的文章就介绍到这了,更多相关go if优化内容请搜索脚本之家以前的文章或继续浏览下面的相关文章希望大家以后多多支持脚本之家！