38 lines
907 B
Go
38 lines
907 B
Go
// Go supports _methods_ defined on any coustom defined types.
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package main
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import "fmt"
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type rect struct {
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width, height int
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}
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// This `area` method has a _receiver type_ of `*rect`.
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func (r *rect) area() int {
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return r.width * r.height
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}
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// Methods can be defined for either pointer or value
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// receiver types. Here's an example of a value receiver.
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func (r rect) perim() int {
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return 2*r.width + 2*r.height
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}
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func main() {
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r := rect{width: 10, height: 5}
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// Here we call the 2 methods defined for our struct.
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fmt.Println("area: ", r.area())
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fmt.Println("perim:", r.perim())
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// Go automatically handles conversion between values
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// and pointers for method calls. You may want to use
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// a pointer receiver type to avoid copying on method
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// calls or to allow the method to mutate the
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// receiving struct.
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rp := &r
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fmt.Println("area: ", rp.area())
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fmt.Println("perim:", rp.perim())
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}
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