Introduction to the usage of multiple return values ​​​​of Golang functions

Golang language is increasingly favored by programmers for its efficiency and simplicity. Functions in Golang have the ability to return one or more values, which provides them with greater flexibility and scalability. This article will introduce the usage of multiple return values ​​​​of Golang functions.

Declaring a function with multiple return values ​​in Golang is very simple, just add multiple types to the function signature. For example, the following function will return two values ​​of type int:

func foo() (int, int) {
  return 1, 2
}

When calling this function, you can use multiple variables to receive the values ​​returned by the function:

a, b := foo()

You can also pass an underscore "_" placeholder to ignore a certain return value of a function:

a, _ := foo()

Multiple return values ​​are very useful, especially when handling errors. In this case, we can check whether the code executed successfully by returning a boolean value and an error message. For example, the following function returns a boolean value and an error:

func bar() (bool, error) {
  if somethingErroneous {
    return false, errors.New("something went wrong")
  }
  return true, nil
}

When using this function, we can check the returned boolean value and print the error if necessary: ​​

ok, err := bar()
if !ok {
  log.Fatal(err)
}

Another common use case is Return a pointer to a value and an error:

func baz() (*MyStruct, error) {
  myStruct := &MyStruct{}
  if somethingErroneous {
    return nil, errors.New("something went wrong")
  }
  return myStruct, nil
}

Note that if the pointer is nil, we assume the function fails and returns an error.

Multiple return values ​​are especially suitable for situations where a function needs to return multiple results when processing a large amount of data. For example, the following function will return the minimum and maximum values ​​in a slice of arbitrary length:

func minMax(numbers []int) (int, int) {
  min, max := numbers[0], numbers[0]
  for _, num := range numbers {
    if num < min {
      min = num
    }
    if num > max {
      max = num
    }
  }
  return min, max
}

In addition to using multiple return values ​​to improve the readability and robustness of your code, it also helps to improve the readability and robustness of your code. performance. In some cases, using multiple return values ​​can reduce the running time of your code by avoiding additional memory allocations after a function call.

In this article, we introduced practical use cases of Golang functions returning multiple values. Using functions with multiple return values ​​makes our code more flexible, easier to read, and more robust. If you haven't tried functions with multiple return values, add them to your code base to improve code quality and performance.

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