Explain the use of Go's defer statement for scheduling function calls to be executed later?

Question

Jayant Kumar · Accepted Answer

In Go, the defer statement is used to schedule a function call to be executed just before the function it's declared in returns. This is often used for cleanup tasks or for tasks that need to be performed after a function has completed, regardless of whether an error occurred or not.
The defer statement can be used to schedule multiple function calls, and they are executed in a last-in, first-out (LIFO) order. This means that the most recently scheduled function call is executed first, and the first scheduled function call is executed last.
The defer statement can be useful in a number of situations, such as:

Closing resources, such as files or network connections
Unlocking mutexes or releasing other synchronization primitives
Logging errors or other information
Recovering from panics

Here is an example of using defer to close a file:
func readFile(filename string) ([]byte, error) {
    f, err := os.Open(filename)
    if err != nil {
        return nil, err
    }
    defer f.Close()

return ioutil.ReadAll(f)
}

In this example, the os.Open function is used to open a file, and if an error occurs, it's returned immediately. If the file is successfully opened, a defer statement is used to schedule a call to the Close method on the file, which will be executed just before the function returns. Finally, the ioutil.ReadAll function is used to read the contents of the file and return them.
Using defer in this way ensures that the file will always be closed, even if an error occurs while reading the contents.

Explain the use of Go's defer statement for scheduling function calls to be executed later?

Similar Questions

Explain the use of Go's defer statement for scheduling function calls to be executed later?

Jayant Kumar @jayantkumar314

Similar Questions