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To check Go language function return value elegantly, you can use the following two methods: Use error value: This is a common method of handling errors. If the function returns a non-nil value, it means an error occurred. Use multiple return values: When a function needs to return multiple values, multiple return values can be used. The first return value is usually the main value, and subsequent return values can be used for error handling or other information.
How to elegantly check the function return value in Go language
In Go language, a function can return multiple values by to return errors or other information. It is important to check these values to make sure they are as expected. Here are two common ways to check function return values:
1. Using error values
This is the most common way to handle errors. The error
type is a built-in type that indicates that an error has occurred when a function returns a non-nil value.
func someFunction() error { // 执行一些操作 if err != nil { return err } } func main() { err := someFunction() if err != nil { // 处理错误 } }
2. Use multiple return values
When a function needs to return multiple values, you can use multiple return values. The first return value is usually the main value, and subsequent return values can be used for error handling or other information.
func someFunction() (string, error) { // 执行一些操作 if err != nil { return "", err } return "成功", nil } func main() { value, err := someFunction() if err != nil { // 处理错误 } }
Practical case
Let us consider a file reading example where the return value of a function needs to be checked:
import ( "fmt" "io/ioutil" "os" ) func readFile(filename string) ([]byte, error) { return ioutil.ReadFile(filename) } func main() { data, err := readFile("myfile.txt") if err != nil { if os.IsNotExist(err) { fmt.Println("文件不存在") } else { fmt.Printf("读取文件时出错: %v", err) } return } fmt.Println(string(data)) }
In this example, ## The #readFile function uses an error value to indicate file read errors. In the
main function we check for errors and take different actions depending on the error type.
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