4
Function types and values
source link: https://yourbasic.org/golang/function-pointer-type-declaration/
Go to the source link to view the article. You can view the picture content, updated content and better typesetting reading experience. If the link is broken, please click the button below to view the snapshot at that time.
Function types and values
yourbasic.org/golang
Function types and function values can be used and passed around just like other values:
type Operator func(x float64) float64
// Map applies op to each element of a.
func Map(op Operator, a []float64) []float64 {
res := make([]float64, len(a))
for i, x := range a {
res[i] = op(x)
}
return res
}
func main() {
op := math.Abs
a := []float64{1, -2}
b := Map(op, a)
fmt.Println(b) // [1 2]
c := Map(func(x float64) float64 { return 10 * x }, b)
fmt.Println(c) // [10, 20]
}The second call to Map uses a function literal (or lambda).
See Anonymous functions and closures
for more about lambdas in Go.
Details
A function type describes the set of all functions with the same parameter and result types.
-
The value of an uninitialized variable of function type is
nil. - The parameter names are optional.
The following two function types are identical.
func(x, y int) int
func(int, int) intFurther reading
Anonymous functions and closures
Share:
Recommend
About Joyk
Aggregate valuable and interesting links.
Joyk means Joy of geeK