Go has a builtin type for errors. In Go, an error is the last return value (They have type error).

The line errors.New creates a new error with a message. If there is no error, you can return the nil value.

Go Error Handling with Errors Package

Go is a powerful programming language that has become increasingly popular among developers due to its simplicity and efficiency. One of the key features of Go is its built-in error type, which allows for effective error handling in programs.

To create a new error message in Go, developers can use the errors.New() function. This function creates a new error with a specified message. If there is no error, the nil value can be returned.

Here is an example of how to use the errors.New() function:

package main

import (
    "errors"
    "fmt"
)

func do() (int, error) {
    return -1, errors.New("Something wrong")
}

func main() {
    fmt.Println(do())
}

In this example, the do() function returns an error using the errors.New() function. The main() function then prints out the error message returned by the do() function.

When you run this program, the output will be:

-1 Something wrong

Developers can also combine both the return values from a function that returns an error message, as shown in the following example:

r, e := do()
if r == -1 {
    fmt.Println(e)
} else {
    fmt.Print("Everything went fine\n")
}

This example demonstrates how to use the do() function to return both the return value and an error message. The r variable captures the return value, while the e variable captures the error message. The if statement then checks if the return value is equal to -1. If it is, the error message is printed out. Otherwise, the message “Everything went fine” is printed out.

In conclusion, Go’s built-in error type and errors.New() function provide a simple and effective way to handle errors in programs. By incorporating these features into your code, you can ensure that your programs run smoothly and efficiently, even when unexpected errors occur.