Error calling method from signal - button

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:bust_in_silhouette: Asked By TraitPhoe

I’m trying to make a simple ax^2 + bx + c calculator in Godot which will tell an answer by pressing a button int the interface, but when I press the button I get an error:
E 0:00:02.160 emit_signal: Error calling method from signal ‘pressed’: 'Node2D(': Method expected 1 arguments, but called with 0..

Here is the code

func _on_LineA_text_entered(A):
	var a = A

	print("a=", A)

func _on_LineB_text_entered(B):
	var b = B

	print("b=", B)
func _on_LineC_text_entered(C):
	var c = C
	print("c=", C)

func _on_Button_pressed(a, b, c):
		var x1 = a + b + c
:bust_in_silhouette: Reply From: SteveSmith

I’d hazard a guess that _on_Button_pressed() should have no arguments if it’s being called directly from an actual button control. You need to store a, b and c in top-level vars, or get them from the LineEdit controls, in order to use them inside _on_Button_pressed().

:bust_in_silhouette: Reply From: cassie

The pressing of the button fires off _on_Button_pressed, but doesn’t pass arguments at all which is why your error says that. Refactor your code so that _on_Button_pressed doesn’t need args, but instead works with local vars set by your other functions.

Now I understand but I don’t know how to change variables on top with local variables in functions. If I type

var a = 0

func _on_LineA_text_entered(A):
	var a = A

func _on_Button_pressed():
		var x1 = a 

It will still print “0” and not whatever you typed in LineEdit

TraitPhoe | 2023-02-09 16:24

Easy fix, see in the _on_LineA_text_entered() you’re creating a new a, what’s called a local variable. It will only have the value you give it within that function, and will be destroyed afterwards. Change the line var a = A to a = A and you’ll be using the one from the top of the file instead.

cassie | 2023-02-09 16:32

Thanks! It worked and counts discriminant with x1 and x2 very well. I’ll make it more flexible and polish it later

TraitPhoe | 2023-02-09 17:51