One question about function pointer

Mojo
1

Hello,
I’m new one on Mojo.
How to pass one function pointer(address or name) as a parameter in another function?

When I checked doc, only an example to show pass class method as function parameter.
How about pure function ?

2

Hi @RobertD,
A standalone function should be passable in the same way as a struct method. Would you like to prove an example of what you tried and what has not worked out?

3

Hello Samufi,
Thanks for your reply.

For example:
def add(val_1: Int, val_2: Int) → Int:
return vaL_1 + val_2

def sub(val_1: Int, val_2: Int) → Int:
return vaL_1 - val_2

I want to have a function oper, it can be used as below:
oper(add, 12, 23)
oper(sub, 35, 12)

How to declare the function of oper is Mojo?
In c, it might be like below:
int oper(int (*f)(int, int), int val_1, int val_2) {
return f(val_1, val_2);
}

4

For a detailed description of that, please have a look here: Mojo Closures 2026

In your case, you can pass the function as a parameter (rather than an argument):

def oper[f: def(Int, Int) thin -> Int](val_1: Int, val_2: Int) -> Int:
   return f(val_1, val_2)

One hint: on the Mojo Discord, there is an AI bot channel where you can find answers to such questions quite quickly.