A built-in type representing a method or a standalone function. [Callable] is a built-in [Variant] type that represents a function. It can either be a method within an [Object] instance, or a standalone function not related to any object, like a lambda function. Like all [Variant] types, it can be stored in variables and passed to other functions. It is most commonly used for signal callbacks. [b]Example:[/b] [codeblocks] [gdscript] func print_args(arg1, arg2, arg3 = ""): prints(arg1, arg2, arg3) func test(): var callable = Callable(self, "print_args") callable.call("hello", "world") # Prints "hello world ". callable.call(Vector2.UP, 42, callable) # Prints "(0, -1) 42 Node(node.gd)::print_args". callable.call("invalid") # Invalid call, should have at least 2 arguments. [/gdscript] [csharp] // Default parameter values are not supported. public void PrintArgs(Variant arg1, Variant arg2, Variant arg3 = default) { GD.PrintS(arg1, arg2, arg3); } public void Test() { // Invalid calls fail silently. Callable callable = new Callable(this, MethodName.PrintArgs); callable.Call("hello", "world"); // Default parameter values are not supported, should have 3 arguments. callable.Call(Vector2.Up, 42, callable); // Prints "(0, -1) 42 Node(Node.cs)::PrintArgs". callable.Call("invalid"); // Invalid call, should have 3 arguments. } [/csharp] [/codeblocks] In GDScript, it's possible to create lambda functions within a method. Lambda functions are custom callables that are not associated with an [Object] instance. Optionally, lambda functions can also be named. The name will be displayed in the debugger, or when calling [method get_method]. [codeblock] func _init(): var my_lambda = func (message): print(message) # Prints Hello everyone! my_lambda.call("Hello everyone!") # Prints "Attack!", when the button_pressed signal is emitted. button_pressed.connect(func(): print("Attack!")) [/codeblock] Constructs an empty [Callable], with no object nor method bound. Constructs a [Callable] as a copy of the given [Callable]. Creates a new [Callable] for the method named [param method] in the specified [param object]. Returns a copy of this [Callable] with one or more arguments bound. When called, the bound arguments are passed [i]after[/i] the arguments supplied by [method call]. See also [method unbind]. [b]Note:[/b] When this method is chained with other similar methods, the order in which the argument list is modified is read from right to left. Returns a copy of this [Callable] with one or more arguments bound, reading them from an array. When called, the bound arguments are passed [i]after[/i] the arguments supplied by [method call]. See also [method unbind]. [b]Note:[/b] When this method is chained with other similar methods, the order in which the argument list is modified is read from right to left. Calls the method represented by this [Callable]. Arguments can be passed and should match the method's signature. Calls the method represented by this [Callable] in deferred mode, i.e. during the idle frame. Arguments can be passed and should match the method's signature. [codeblock] func _ready(): grab_focus.call_deferred() [/codeblock] Calls the method represented by this [Callable]. Unlike [method call], this method expects all arguments to be contained inside the [param arguments] [Array]. Return the bound arguments (as long as [method get_bound_arguments_count] is greater than zero), or empty (if [method get_bound_arguments_count] is less than or equal to zero). Returns the total amount of arguments bound (or unbound) via successive [method bind] or [method unbind] calls. If the amount of arguments unbound is greater than the ones bound, this function returns a value less than zero. Returns the name of the method represented by this [Callable]. If the callable is a lambda function, returns the function's name. Returns the object on which this [Callable] is called. Returns the ID of this [Callable]'s object (see [method Object.get_instance_id]). Returns the 32-bit hash value of this [Callable]'s object. [b]Note:[/b] [Callable]s with equal content will always produce identical hash values. However, the reverse is not true. Returning identical hash values does [i]not[/i] imply the callables are equal, because different callables can have identical hash values due to hash collisions. The engine uses a 32-bit hash algorithm for [method hash]. Returns [code]true[/code] if this [Callable] is a custom callable. Custom callables are created from [method bind] or [method unbind]. In GDScript, lambda functions are also custom callables. Returns [code]true[/code] if this [Callable] has no target to call the method on. Returns [code]true[/code] if this [Callable] is a standard callable. This method is the opposite of [method is_custom]. Returns [code]false[/code] if this callable is a lambda function. Returns [code]true[/code] if the callable's object exists and has a valid method name assigned, or is a custom callable. Perform an RPC (Remote Procedure Call). This is used for multiplayer and is normally not available, unless the function being called has been marked as [i]RPC[/i]. Calling this method on unsupported functions will result in an error. See [method Node.rpc]. Perform an RPC (Remote Procedure Call) on a specific peer ID (see multiplayer documentation for reference). This is used for multiplayer and is normally not available unless the function being called has been marked as [i]RPC[/i]. Calling this method on unsupported functions will result in an error. See [method Node.rpc_id]. Returns a copy of this [Callable] with a number of arguments unbound. In other words, when the new callable is called the last few arguments supplied by the user are ignored, according to [param argcount]. The remaining arguments are passed to the callable. This allows to use the original callable in a context that attempts to pass more arguments than this callable can handle, e.g. a signal with a fixed number of arguments. See also [method bind]. [b]Note:[/b] When this method is chained with other similar methods, the order in which the argument list is modified is read from right to left. [codeblock] func _ready(): foo.unbind(1).call(1, 2) # Calls foo(1). foo.bind(3, 4).unbind(1).call(1, 2) # Calls foo(1, 3, 4), note that it does not change the arguments from bind. [/codeblock] Returns [code]true[/code] if both [Callable]s invoke different targets. Returns [code]true[/code] if both [Callable]s invoke the same custom target.