What is the error causing my character delay its response when press a key? - actionscript-3

Question

I have some problems with my character's walking command. It delays its movement for a bit before it actually moves. And then at times it completely ignores the command to stop walking when I released the key.
Code:
import flash.events.KeyboardEvent;
import flash.ui.Keyboard;
import flash.display.MovieClip;
import flash.events.Event;
import flash.display.Stage;
hero.gotoAndStop(1);
var rightPressed: Boolean = new Boolean(false);
var leftPressed: Boolean = new Boolean(false);
var upPressed: Boolean = new Boolean(false);
var downPressed: Boolean = new Boolean(false)
var heroSpeed: Number = 10;
var keys: Array = [];
stage.addEventListener(KeyboardEvent.KEY_DOWN, keyDownHandler);
stage.addEventListener(KeyboardEvent.KEY_UP, keyUpHandler);
stage.addEventListener(Event.ENTER_FRAME, gameLoop);
stage.addEventListener(KeyboardEvent.KEY_DOWN, onKeyDown);
stage.addEventListener(KeyboardEvent.KEY_UP, onKeyUp);
function keyDownHandler(KeyEvent: KeyboardEvent): void {
if (keys[Keyboard.RIGHT]) {
rightPressed = true;
} else if (keys[Keyboard.LEFT]) {
leftPressed = true;
} else if (keys[Keyboard.DOWN]) {
downPressed = true;
} else if (keys[Keyboard.UP]) {
upPressed = true;
}
}
function keyUpHandler(KeyEvent: KeyboardEvent): void {
if (keys[Keyboard.RIGHT]) {
rightPressed = false;
hero.gotoAndStop(4)
} else if (keys[Keyboard.LEFT]) {
leftPressed = false;
hero.gotoAndStop(2)
} else if (keys[Keyboard.DOWN]) {
downPressed = false;
hero.gotoAndStop(1);
} else if (keys[Keyboard.UP]) {
upPressed = false;
hero.gotoAndStop(3);
}
}
function gameLoop(loopEvent: Event): void {
if (rightPressed) {
hero.x += heroSpeed;
hero.gotoAndStop(8)
}
if (leftPressed) {
hero.x -= heroSpeed;
hero.gotoAndStop(6)
}
if (downPressed) {
hero.y += heroSpeed;
hero.gotoAndStop(5);
}
if (upPressed) {
hero.y -= heroSpeed;
hero.gotoAndStop(7);
}
}
function onKeyDown(e: KeyboardEvent): void {
keys[e.keyCode] = true;
}
function onKeyUp(e: KeyboardEvent): void {
keys[e.keyCode] = false;
}
Warnings:
Scene 1, Layer 'Actions', Frame 1, Line 68, Column 10 Warning: 1090: Migration issue: The onKeyDown event handler is not triggered automatically by Flash Player at run time in ActionScript 3.0. You must first register this handler for the event using addEventListener ( 'keyDown', callback_handler).
Scene 1, Layer 'Actions', Frame 1, Line 72, Column 10 Warning: 1090: Migration issue: The onKeyUp event handler is not triggered automatically by Flash Player at run time in ActionScript 3.0. You must first register this handler for the event using addEventListener ( 'keyUp', callback_handler).

Answer 1

You should get rid of the two extra KeyboardEvent handlers (onKeyUp and onKeyDown), and move the code you have there into keyUpHandler and keyDownHandler. That will solve those migration warnings (because onKeyUp and onKeyDown were special methods in AS2), and it may be the solution to your other problem: I guess sometimes the onKeyDown handler gets executed after keyDownHandler, which means the boolean values in your array are not set yet and no movement will start.
Even better: also get rid of the array with booleans (and keys! you're abusing an Array for Dictionary use) and do it like this:
function keyDownHandler(KeyEvent: KeyboardEvent): void {
if (event.keyCode==Keyboard.RIGHT]) {
rightPressed = true;
}
//etc
}