Missing return at end of function error in Golang

package main

import "fmt"

func calculateSum(a, b int) int {
    sum := a + b
    fmt.Println("The sum is: ", sum)
}

func main() {
    calculateSum(10, 20)
}

In this program, we define a function calculateSum that takes two integer arguments a and b, calculates their sum, and prints the sum to the console using the fmt.Println() function. We then call this function with the values 10 and 20 in the main() function.

However, when we try to compile and run this program, we will encounter the following error:

./main.go:7:1: missing return at end of function

This error occurs because the calculateSum function is expected to return an integer value, but there is no return statement at the end of the function to provide a value. To fix this error, we need to add a return statement that returns the sum value, like this:

package main

import "fmt"

func calculateSum(a, b int) int {
    sum := a + b
    fmt.Println("The sum is: ", sum)
    return sum
}

func main() {
    calculateSum(10, 20)
}

In this modified program, we add a return statement at the end of the calculateSum function that returns the value of the sum variable. This code will compile and run without any errors.

In summary, the "missing return at end of function" error in Golang occurs when a function is missing a return statement at the end. To fix this error, the developer needs to add a return statement that provides a value of the appropriate type.