Call a Method by Name

How do I invoke a Java method when given the method name as a string?

Coding from the hip, it would be something like:

java.lang.reflect.Method method;
try {
  method = obj.getClass().getMethod(methodName, param1.class, param2.class, ..);
} catch (SecurityException e) { ... }
  catch (NoSuchMethodException e) { ... }

The parameters identify the very specific method you need (if there are several overloaded available, if the method has no arguments, only give methodName).

Then you invoke that method by calling

try {
  method.invoke(obj, arg1, arg2,...);
} catch (IllegalArgumentException e) { ... }
  catch (IllegalAccessException e) { ... }
  catch (InvocationTargetException e) { ... }

Again, leave out the arguments in .invoke, if you don't have any. But yeah. Read about Java Reflection

How to call a method by name (String) in Java?

You cannot. Java doesn't treat functions as first class objects, because it doesn't have functional features like Python or C#.

You can create a Command interface and pass that object reference:

public interface Command {
    void execute(Object [] args);
}

How to call method by Name from variable value in perl?

This is not really recommended because there are safety issues, but you can use the name of a subroutine to call it:

my $method = "hello";
{
  no strict 'refs';
  &{$method}();  # same as hello()
}

This &{...}() syntax “dereferences” the subroutine name and calls it.

If you're calling methods on an object, you can skip the no strict 'refs' part:

my $method = 'name';
$object->$method();  # same as $object->name

If you only want to allow a couple of subroutines, it would be much better to store them in a hash table:

my %known_functions = (
  hello => \&hello,  # \& stores a reference to a subroutine 
  bye => \¬_hello,  # added benefit: renaming them
);

# define the functions somewhere
sub hello { ... }
sub not_hello { ... }

# can't access secret methods unless they are added to the hash table
sub secret { ... }

# use a hash lookup and call the method
my $method = 'hello';
$known_functions{$method}();

How to call method by name using Kotlin Reflection?

try this:

obj::class.members.firstOrNull { it.name == "methodName" }?.call(argument1, argument2, ...)

Call a Python method by name

Use the built-in getattr() function:

class Foo:
    def bar1(self):
        print(1)
    def bar2(self):
        print(2)

def call_method(o, name):
    return getattr(o, name)()

f = Foo()
call_method(f, "bar1")  # prints 1

You can also use setattr() for setting class attributes by names.

Retrieving the calling method name from within a method

I don't think it can be done without tracing the stack. However, it's fairly simple to do that:

StackTrace stackTrace = new StackTrace();
MethodBase methodBase = stackTrace.GetFrame(1).GetMethod();
Console.WriteLine(methodBase.Name); // e.g.

However, I think you really have to stop and ask yourself if this is necessary.

Calling a function of a module by using its name (a string)

Given a module foo with method bar:

import foo
bar = getattr(foo, 'bar')
result = bar()

getattr can similarly be used on class instance bound methods, module-level methods, class methods... the list goes on.

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