Functions in Go Language

Introduction

Functions are a group of programming statements. Functions provide us with the concept of reusability which promotes code reusability, Reducing the usage of memory and development time.   The function allows you to extract a commonly used block of code into a single component.

In Golang, Every code execution starts with the main() function which acts as an entry point for the execution flow.

Syntax

Function Declaration

The declaration of the function contains

• func: It is a keyword in the language, which is used to create a Golang function.
• function_name: It is the name of the function.
• Parameter-list: It contains the name and the type of the function inputs.
• Return_type: Returns types are optional in Golang. It contains details about what will a function return if we add a return type to our function, It is mandatory to pass a return value in our function.

Function Calling

Golang Function can be called in a below way.

Example

We will create an example of simple addition. A function add is created with the func keyword before it. the func keyword tells Go that this piece of code is a function. Later we invoked the function in the main() using its name.

Output:

Try on Playground.

Function Arguments

Call by Value

When we pass values of variables to a function as parameters, those functions are known as Call By Value. Changes made to the function variable won't update the original variables as we pass copies of those.

Output:

Try on Playground

Call by Reference

While Calling a function, If we pass the address of a variable instead of a value, Those functions are known as Call by Reference. Changes made to function variables update the original variables as we are passing the addresses of those.

Output:

Try on Playground

More Examples

Let's see more examples of the Golang function.

Golang Functions Returning Multiple Values

Output:

Try on Playground.

The Return Values of a Function can be Named in Golang

Output:

Try on Playground.

Golang Passing Address to a Function

Output:

Try on Playground.

Anonymous Functions in Golang

Output:

Try on Playground.