d3-101/hello-d3.html

<!DOCTYPE html>
<head>
    <meta charset="utf-8">
    <style>
        body {
            color: red;
            font-family: sans-serif;
        }
    </style>
</head>
<body>
    <script src="http://d3js.org/d3.v2.js"></script>
    <script>
        var a = 5; //global scope is forced without the use of var

        function return_global_a() {
            return a;
        }
        function return_global_b() {
            return b;
        }

        function test1() {
            console.log("a in function scope:",a);
            console.log("a in global scope:",return_global_a());
        };

        function test2() {
            var a=2;
            console.log("a in function scope:",a);
            console.log("a in global scope:",return_global_a());
        };

        function test3() {
            a=3
            console.log("a in function scope:",a);
            console.log("a in global scope:",return_global_a());
        };

        function test4() {
            var a=7
            console.log("a in function scope:",a);
            console.log("a in global scope:",return_global_a());
        };
        function test5() {
            b=2
            console.log("b in function scope:",b);
            console.log("b in global scope:",return_global_b());
        };
        function test6() {
            console.log("b in function scope:",b);
            console.log("b in global scope:",return_global_b());
        };

        d3.select("body").append("p").text("D3-101")
        
    </script>
</body>