Higher Order Functions in Golang
A Higher-Order function is a function that receives a function as an argument or returns the function as output.
Higher order functions are functions that operate on other functions, either by taking them as arguments or by returning them.
Passing Functions as Arguments to other Functions
Example
package main
import "fmt"
func sum(x, y int) int {
return x + y
}
func partialSum(x int) func(int) int {
return func(y int) int {
return sum(x, y)
}
}
func main() {
partial := partialSum(3)
fmt.Println(partial(7))
}
Output
10
In the program above, the partialSum function returns a sum function that takes two int arguments and returns a int argument.
Returning Functions from other Functions
Example
package main
import "fmt"
func squareSum(x int) func(int) func(int) int {
return func(y int) func(int) int {
return func(z int) int {
return x*x + y*y + z*z
}
}
}
func main() {
// 5*5 + 6*6 + 7*7
fmt.Println(squareSum(5)(6)(7))
}
Output
110
In the program above, the squareSum function signature specifying that function returns two functions and one integer value.
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