What is it

func HelloWorld() string {
  return "Hello World"
}

• Function name fo HelloWorld
• returns string type

func add(x int, y int) int {
	return x + y
}

• Defines a function of name add
• Defines Params
  • accept parameter of x which is of type int
  • accept parameter of y which is also of type int
• Defines Return type
  • function returns type of int

Return deconstruction

When you have multiple return values on a function, it must be wrapped in a parenthesis ()

func twoReturns() (r1 string, r2 string) {
	// ...
}

When a function returns a err as second return value, you can use it to catch error

// package.method() has two return values
result, err := package.method()
if err != nil {
	log.Printf("error calling package.method: %v", err)
}

Parameter and Type Breakdown

First parameter is stating that function operates on an object of defined name and type

• item is a struct defined
• item is used via item.id and item.price
• This is where the dependency injection using fx would be made available

func (m_mod *MathModule) FunctionName() () {
	arithmatics := m_mod.arithmatics
}

process() is the name of the function with standard parameter

• In this case, no parameter is passed to the function

(string, int) states that the function has multiple return values of string and integer types

func (i item) process() (string, int) { 
	return i.id, i.price
}

// above the file
type item struct { 
	id string 
	price  int 
}