In Go, the meaning of interface is no different from that of interfaces in other languages. Interface is understood as a type of specification or convention. Does a type "implement" an interface? It depends on whether this type implements all methods defined in the interface. (Recommended: go language tutorial)
1. The definition and use of interfaces.
For example,
type I interface{ Get() int Put(int) }
This paragraph defines an interface, which contains two functions Get and Put
Okay, one of my interfaces This interface is implemented:
type S struct {val int} func (this *S) Get int { return this.val } func (this *S)Put(v int) { this.val = v }
This structure S is the implementation of interface I
2, empty interface
For empty Interface interface{} is actually very similar to the concept of generics. Any type implements the empty interface.
The following is an example:
A function implements such a function:
Take any object as a parameter. If the object implements interface I, then call interface I The Get method
Many languages have this logic:
function g(obj){ if (obj is I) { return (I)obj.Get() } }
This is implemented in Go:
func g(any interface{}) int { return any.(I).Get() }
Any.(I) here is very semantic ? "Any object that implements the I interface"
3. How to write interface in Go:
Let's look at a few interface examples:
func SomeFunction(w interface{Write(string)}){ w.Write("pizza") }
In this example, the interface is directly defined in the parameter, which is very special...
func weirdFunc( i int ) interface{} { if i == 0 { return "zero" } return i; }
In this example, since it is possible to return string or int, the return value is set to interface , which can be seen in large numbers in Go packages.
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