How to Invoke Methods with Reflection in Go

Go does not have a built-in reflection API to invoke methods by name like Java or C#; instead, you use the reflect package to get a Method value and call its Call function. Use reflect.ValueOf to get the value, MethodByName to find the method, and Call with a slice of reflect.Value arguments to execute it.

import "reflect"

func invoke(obj any, methodName string, args ...any) any {
    v := reflect.ValueOf(obj)
    method := v.MethodByName(methodName)
    if !method.IsValid() {
        panic("method not found")
    }
    in := make([]reflect.Value, len(args))
    for i, arg := range args {
        in[i] = reflect.ValueOf(arg)
    }
    out := method.Call(in)
    if len(out) == 0 {
        return nil
    }
    return out[0].Interface()
}

Reflection in Go lets your program inspect and interact with its own structure while it is running. You use it to find and run functions or access fields when you don't know their names until the program starts. Think of it like a universal remote that can press any button on a device without needing a specific button for each one.