关于#javascript#的问题，请各位专家解答！

代码不对显示不出来？

html>
<html>
    <head>
        <meta charset="UTF-8">
        <title>作业title>
    head>
    <script type="text/javascript">
        var str='Abcdefg Abcdefg Abcdefg Abcdefg Abcdefg';
        var a=str.split("");
        document.write(a)
        var count=0;
        
        for(var i=0;ilength;i++)
        {
            var b=arr[i].indexOf("def");
            if(b>=0)
            count++;
        }
        document.write('满足');
    script>
    <body>
    body>
html>

<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8">
        <title>作业</title>
    </head>
    <script type="text/javascript">
        var str='Abcdefg Abcdefg Abcdefg Abcdefg Abcfefg';
        var count=0;
        var arr=str.split(" ");
        for(var i=0;i<arr.length;i++){
        var b=arr[i].indexOf("def");
         if(b>=0) count++;
         }
        document.write("总共"+arr.length+"个");
        document.write('<br />');
        document.write("满足"+count+"个");
    </script>
    <body>
    </body>
</html>