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64 lines
926 B
Markdown
64 lines
926 B
Markdown
---
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id: 03a6cd46-e6fb-46a8-96f7-16c37a6d140a
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title: Golang methods
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---
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# Basics
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In Go methods can be defined on [struct](20200828181259-structs) and
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non-struct types. In this case a **receiver** argument ias passed
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between \`func\` keyword and the method name (\`Abs\`):
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``` go
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package main
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import (
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"fmt"
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"math"
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)
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type Vertex struct {
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X, Y float64
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}
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func (v Vertex) Abs() float64 {
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return math.Sqrt(v.X*v.X + v.Y*v.Y)
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}
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func main() {
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v := Vertex{3, 4}
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fmt.Println(v.Abs())
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}
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```
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# Pointers
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To modify struct values methods must be declared with pointer receivers:
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``` go
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package main
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import (
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"fmt"
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"math"
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)
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type Vertex struct {
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X, Y float64
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}
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func (v Vertex) Abs() float64 {
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return math.Sqrt(v.X*v.X + v.Y*v.Y)
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}
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func (v *Vertex) Scale(f float64) {
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v.X = v.X * f
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v.Y = v.Y * f
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}
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func main() {
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v := Vertex{3, 4}
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v.Scale(10)
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fmt.Println(v.Abs())
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}
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```
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