To **pass** a **function** as a **parameter** to **another** **function**, **“****define the parameter type as a function signature”**. Function signatures describe a function’s input and output types without specifying its implementation.

**Example**

```
package main
import (
"fmt"
)
// Define a function type called "operation"
type operation func(int, int) int
// Add is a simple function that adds two integers
func Add(x, y int) int {
return x + y
}
func Subtract(x, y int) int {
return x - y
}
func PerformOperation(f operation, x, y int) int {
return f(x, y)
}
func main() {
a, b := 21, 19
// Pass the Add function as a parameter to PerformOperation
result := PerformOperation(Add, a, b)
fmt.Printf("%d + %d = %d\n", a, b, result)
// Pass the Subtract function as a parameter to PerformOperation
result = PerformOperation(Subtract, a, b)
fmt.Printf("%d - %d = %d\n", a, b, result)
}
```

**Output**

```
21 + 19 = 40
21 - 19 = 2
```

In this example, we defined a function type called operation that takes two integers as input and returns an integer. In addition, we defined two functions, **Add()** and **Subtract()**, that match the operation function signature.

The **PerformOperation()** function takes a function of type operation and two integers as parameters.

Inside the **PerformOperation()** function, we called the passed **function f** with the given integers and returned the result.

In the **main()** function, we called **PerformOperation()** with the **Add()** and **Subtract()** functions as parameters and printed the results.

That’s it.

Krunal Lathiya is a Software Engineer with over eight years of experience. He has developed a strong foundation in computer science principles and a passion for problem-solving. In addition, Krunal has excellent knowledge of Distributed and cloud computing and is an expert in Go Language.