Go Functions

In Go, functions are the basic building blocks. A function is used to break a large problem into smaller tasks. We can invoke a function several times, hence functions promote code reusability. There are 3 types of functions in Go:

Normal functions with an identifier
Anonymous or lambda functions
Method (A function with a receiver)

Function parameters, return values, together with types, is called function signature.

Function cannot be declared inside another function. If we want to achieve this, we can do this by anonymous function.

Go Function Example

package main
import "fmt"
type Employee struct {
   fname string
   lname string
}
func (emp Employee) fullname(){
   fmt.Println(emp.fname+" "+emp.lname)
}
func main() {
   e1 := Employee{ "John","Ponting"}
   e1.fullname()
}

Output:

John Ponting

Go Function with Return

Let's see an example of function with return value.

package main
import (
   "fmt"
)
func fun() int {
   return 123456789
}
func main() {
   x := fun()
   fmt.Println(x)
}

Output:

Go Function with Multiple Return

Let's see an example of a function which takes n number of type int as argument and returns two int values. The return values are filled in the calling function in a parallel assignment.

Go function multiple return example

package main
import (
   "fmt"
)
func main() {
   fmt.Println(addAll(10,15,20,25,30))
}
func addAll(args ... int)(int,int)  {
   finalAddValue:=0
   finalSubValue:=0
   for _,value  := range args{
      finalAddValue += value
      finalSubValue -= value
   }
   return finalAddValue,finalSubValue
}

Output: