Increment

Abstract AS2

@push(+@pop() + 1);

Note: The unary + operator is used to convert the argument to a number.

Adobe documentation

ActionIncrement

ActionIncrement pops a value from the stack, converts it to number type, increments it by 1, and pushes it back to the stack.

FieldTypeComment
ActionIncrementACTIONRECORDHEADERActionCode = 0x50

ActionIncrement does the following:

  1. Pops the number off of the stack.
  2. Pushes the result on to the stack.