Go Concepts - Functions
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External
- Function type specification https://golang.org/ref/spec#Function_types
Internal
Function Definition
A function declaration starts with the func keyword and it consists in a series of statements applied on a number of inputs, resulting in a number of outputs. Same inputs will always result in the same outputs. Function do not depend on a type instance's state. Functions are conceptually different from methods.
Syntax
func [receiver] <name>( [parameter-identifier1] [type1], [parameter-identifier2] [type2], ...) ( [return-type1], [return-type2], ...) { statement1 statement2 ... return <return-value1>, <return-value2> }
Examples:
func add(a int, b int) (int) { return a + b; }
Built-in Functions
make() | append() | copy() | delete() | . |
new() | len() | cap() | . | . |
. | . | . | . | . |
Closures
Anonymous function that capture local variables.
More about closures is available here.
Methods
A method defines the behavior of a type, and it relies on the state of an instance of the type. The method will - and it is supposed to - change the state. From this point of view, the method is conceptually different from a function.
A method is always exported by the package it is enclosed in.