global-scope.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Javascript</title>
</head>
<body>


<h1>Hello bb</h1>
<div id="output"></div>


<script>
    // declare a function global scope

     var constant = 32;

     function celsiusToFarenheit( temperature )

    {
        var farenheitTemp = temperature * 9/5 + constant;
        return farenheitTemp;
    }
     
     output.innerHTML = celsiusToFarenheit(100);

    
    //  globas scope

    var x = 15;
    if (x < 20)
    {
        var y = x;
    }

        var z = y
    output.innerHTML = z;

    
</script>  
</body>
</html>