What is the method
In fact, as long as you understand this principle, you can basically understand it. The problem mentioned above.
The method is actually a special function, and the receiver is the first parameter passed in implicitly.For example
type test struct{
name string
}
func (t test) TestValue() {
}
func (t *test) TestPointer() {
}
func main(){
t := test{}
m := test.TestValue
m(t)
m1 := (*test).TestPointer
m1(&t)
} Is it easy to understand? Now let’s add the code to see the difference between pointers and non-pointers.
type test struct{
name string
}
func (t test) TestValue() {
fmt.Printf("%p\n", &t)
}
func (t *test) TestPointer() {
fmt.Printf("%p\n", t)
}
func main(){
t := test{}
//0xc42000e2c0
fmt.Printf("%p\n", &t)
//0xc42000e2e0
m := test.TestValue
m(t)
//0xc42000e2c0
m1 := (*test).TestPointer
m1(&t)
}
I guess some students have already understood that when it is not a pointer After the actual parameters are passed in, the value is copied. So every time TestValue() is called, the value is copied.
So what will be the result if it involves modifying the value?type test struct{
name string
}
func (t test) TestValue() {
fmt.Printf("%s\n",t.name)
}
func (t *test) TestPointer() {
fmt.Printf("%s\n",t.name)
}
func main(){
t := test{"wang"}
//这里发生了复制,不受后面修改的影响
m := t.TestValue
t.name = "Li"
m1 := (*test).TestPointer
//Li
m1(&t)
//wang
m()
} So everyone Students must pay attention when encountering such problems in programming. So what is the relationship between these method sets? Here I borrowed qyuhen’s notes from studying in golang. I also recommend friends who like golang to read this book. , which is very helpful for deepening the understanding of golang.
• Type T method set contains all receiver T methods.
• The type
T methods.• If type S contains anonymous field T, then S method set contains T method.
Although golang is simple and easy to use, it still has many pitfalls. The author encountered many pitfalls in the process of using golang, which will be mentioned in the blog later. Everyone is welcome. discuss together.
• If type S contains anonymous field T, then S's method set contains T T methods.
• Regardless of embedding T or
T, the set of S methods always contains T *T methods.
Conclusion