I am trying to create a moving character and my code is not working?

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In Html and Javascript I am trying to make the character (a letter O) move with the wasd keys. I have tried everything I can, and I can't get it to work. Can you tell me how to do it. Also, can you be pretty specific... I kind of a beginner. Here is the code.

JavaScript

<!DOCTYPE html>
<canvas id="ctx" width="500" height="500" style="border: 1px solid black;">

    <script>

    
    var ctx = document.getElementById("ctx").getContext("2d");

    var player = {
        pressRight: false,
        pressLeft: false,
        pressDown: false,
        pressUp: false,
        x: 250,
        y: 250,
    };

       ctx.font = "100px,arial";
       ctx.fillText("O",player.x,player.y);
    
   document.onkeydown = function (event){

        if(event.keyCode == "D")        //d
                player.pressRight = true;
        else if(event.keyCode == "S")   //s
                player.pressDown = true;
        else if(event.keyCode == "A") //a
                player.pressLeft = true;
        else if(event.keyCode == "W") // w
                player.pressUp = true;
    }
    
    document.onkeyup = function (event){
            if(event.keyCode == "D")        //d
                    player.pressRight = false;
            else if(event.keyCode == "S")   //s
                    player.pressDown = false;
            else if(event.keyCode == "A") //a
                    player.pressLeft = false;
            else if(event.keyCode == "W") // w
                    player.pressUp = false;
    }
    
    function updatePlayerPosition(){
            if(player.pressRight == true)
                    player.x += 10;
            if(player.pressLeft == true)
                    player.x -= 10;
            if(player.pressDown == true)
                    player.y += 10;
            if(player.pressUp == true)
                    player.y -= 10;
    }

    function drawPlayer(){
        ctx.clearRect(0,0,500,500);
        ctx.font = "100px,arial";
        ctx.fillText("O",player.x,player.y);
    }


    function Update(){
        ctx.clearRect(0,0,500,500);
        updatePlayerPosition();
        drawPlayer();
    }

    setInterval(Update,100);
    
</script>

What I have tried:

I have looked up videos and searched as much as I could on the internet and have not figured it out... I sure its user error but I don't know where I'm messing up.

Posted 11-Aug-16 16:49pm

Ghostdragon777

Updated 12-Aug-16 13:13pm

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Karthik_Mahalingam · Accepted Answer · 2016-08-11T18:30:00

Small Correction

KeyCode for <br />
d-> 68<br />
s-> 83<br />
a-> 65<br />
w-> 87

C#

if (event.keyCode == 68)        //d
                  player.pressRight = true;
              else if (event.keyCode == 83)   //s
                  player.pressDown = true;
              else if (event.keyCode == 65) //a
                  player.pressLeft = true;
              else if (event.keyCode ==87) // w
                  player.pressUp = true;

refer :JavaScript Event KeyCodes[^]

Patrice T · Accepted Answer · 2016-08-12T13:13:00

You should learn to use the debugger as soon as possible. Rather than guessing what your code is doing, It is time to see your code executing and ensuring that it does what you expect.

The debugger allow you to follow the execution line by line, inspect variables and you will see that there is a point where it stop doing what you expect.
Debugger - Wikipedia, the free encyclopedia[^]
Mastering Debugging in Visual Studio 2010 - A Beginner's Guide[^]

The debugger is here to show you what your code is doing and your task is to compare with what it should do.
When the code don't do what is expected, you are close to a bug.

I am trying to create a moving character and my code is not working?

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