Add

• Action Code: 0x0a
• Stack: 2 → 1
• SWF version: 4

Legacy numeric addition.

In SWF 4, it corresponded to the operator +.

In SWF 5, this operator is no longer available, since the semantics of + were changed to be the ECMA-262 addition operator. When importing an SWF 4 project in a recent Flash Pro version, the expression left + right is rewritten to Number(left) + Number(right) according to Adobe's documentation.

Abstract AS2

@t0 = +@pop();
@push(+@pop() + @t0);

Note: The unary + operators are used to convert the arguments to numbers.

Adobe documentation

ActionAdd

ActionAdd adds two numbers and pushes the result back to the stack.

Field	Type	Comment
ActionAdd	ACTIONRECORDHEADER	ActionCode = 0x0A

ActionAdd does the following:

1. Pops value A off the stack.
2. Pops value B off the stack.
3. Converts A and B to floating-point; non-numeric values evaluate to 0.
4. Adds the numbers A and B.
5. Pushes the result, A+B, to the stack.