<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <title>JavaScript</title>
</head>
<body>

<!-- <p id="test"></p> //#1 -->

<canvas height="100" width="300" style="border: 2px blue double;">

</canvas>

<script type="text/javascript">

    // window.alert("Hello There"); //worked


    // document.write("Hello There"); //worked

    // document.getElementById("test") .innerHTML = "Hello There"; //#1

    // console.log("Hello there Help me im so alone"); //worked

    /*function ifCommand() {
        var x = 10;
        if (x < 100){
            window.alert(" X smaller then 100");
        }
    }*/ //#2

    /*function elseIfCommand() {
        var x = 15;
        if (x < 10) {
            window.alert("x smal than 10");
        }
        else if (x < 20) {
            window.alert("x smal than 20 and bigger than 10");
        }
    }*/

    var kanvas = document.querySelector("canvas");

    var konteks = kanvas.getContext("2d");
    konteks.moveTo(10,10);
    konteks.lineTo(290,40);
    konteks.stroke();

    var konteks2 = kanvas.getContext("2d");
    konteks2.moveTo(10,40);
    konteks2.lineTo(290,10);
    konteks2.stroke();


</script>

</body>
</html>
Bu şekilde deneyin, javascript kod bloğunu önce değil sonra çağırın.