Error handling mechanism of golang function

The error handling mechanism of Go language functions is to indicate the execution status by returning a value of type error. Error handling methods include: 1. Returning the error value naked; 2. Using fmt.Errorf to wrap the error; 3. Using errors.Is and errors.As to check the error type; 4. Nesting error values ​​to form an error chain.

Error handling mechanism of Go language function

In Go language, a function can return an error value to indicate its execution status. The error type is a built-in interface that represents an error condition. A function can indicate an error by returning an error value or a pointer of type error containing an error value.

Error handling methods

Go language provides a variety of error handling methods:

• Naked return: If the function does not need to handle errors , you can directly return the error value.
• Error wrapping: You can use the fmt.Errorf function to wrap errors and add additional context or information.
• Error type assertion: You can use the errors.Is and errors.As functions to check whether an error is of a specific type.
• Error nesting: Other error values ​​can be stored in the error value to form an error chain.

Practical case

The following is an example of a function that handles errors:

func readFile(filename string) (content []byte, err error) {
    data, err := ioutil.ReadFile(filename)
    if err != nil {
        return nil, fmt.Errorf("ReadFile: %v", err)
    }
    return data, nil
}

In this function, the readFile function returns a byte array and an error value. If the ioutil.ReadFile function encounters an error, an error value will be returned, which will be wrapped and returned to the caller.

Conclusion

By using error handling mechanisms, you can write Go programs that are robust and easy to debug. By returning an error value, a function can communicate error conditions to the caller for appropriate handling.

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