A function is a block of statements that can be used repeatedly in a program.
A function will not execute automatically when a page loads.
A function will be executed by a call to the function.
Create a Function
To create (often referred to as declare) a function, do the following:
- Use the func keyword.
- Specify a name for the function, followed by parentheses ().
- Finally, add code that defines what the function should do, inside curly braces {}.
Syntax
func
FunctionName
() {
// code to be executed
}Call a Function
Functions are not executed immediately. They are "saved for later use", and will be executed when they are called.
In the example below, we create a function named "myMessage()". The opening curly brace ( { ) indicates the beginning of the function code, and the closing curly brace ( } ) indicates the end of the function. The function outputs "I just got executed!". To call the function, just write its name followed by two parentheses ():
Example
package main
import ("fmt")
func myMessage() {
fmt.Println("I just got executed!")
}
func main() {
myMessage() // call the function
}A function can be called multiple times.
Example
package main
import ("fmt")
func myMessage() {
fmt.Println("I just got executed!")
}
func main() {
myMessage()
myMessage()
myMessage()
}Naming Rules for Go Functions
- A function name must start with a letter
- A function name can only contain alpha-numeric characters and underscores ( A-z , 0-9 , and _ )
- Function names are case-sensitive
- A function name cannot contain spaces
- If the function name consists of multiple words, techniques introduced for multi-word variable naming can be used
Tip
Give the function a name that reflects what the function does!