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title
| title |
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| Go Functions |
Go Functions
A function takes zero or more parameters of any type, does some logic with them and may return one or more values. Golang's function syntax is:
func sum(parameter1 int64, parameter2 int64) int64 {
return parameter1+parameter2
}
Here, the name of the function is sum. It takes to parameters, parameter1 and parameter2 of type int64
and returns another int64, the sum of the two parameters.
Return
After a return is reached, the function exits without executing more code.
func sum(parameter1 int64, parameter2 int64) int64 {
return parameter1+parameter2
// Unreachable code
fmt.Printf("Don't print me")
}
Calling a function
The above function would be called like this:
sum(4, 5)
The value of this expression is 9.
Omit parameter type
If two or more consecutive parameters are the same type, it may be stated only once.
function foo(x, y, z int64, name string) {
fmt.Printf("%d %d %d %s", x, y, z, name)
}
Here x, y, and z are type int64, and name is a string.
Returning multiple values
A function can return zero or more values. To return nothing, omit the return type:
function helloWorld() {
fmt.Printf("Hello world!")
}
To return one value specify its type:
function getHelloWorld() string {
return "Hello world!"
}
To return more than one value specify their types, wrapped in () and separated by commas:
function getHelloWorldAndBestLanguage() (string, string) {
return "Hello world!", "Golang"
}
To receive these values, simply declare variables separated by commas like this:
helloWorld, bestLanguage := getHelloWorldAndBestLanguage()
// helloWorld == "Hello world!"
// bestLanguage == "Golang"
Naked returns
You can name the return types so that you don't need to pass variable to the return statement:
func duplicate(s string) (first, second string) {
first = s
last = s
return
}
func main() {
fmt.Println(split("Hello world!")) // ("Hello world!", "Hello world!")
}