html实现9*9乘法表

<style>
  td{
    border:1px solid ;
  }
</style>

  <script>
    var a=1;
    switch(a){
      case 1:alert("number");break;
      case "abc":alert("string");break;
      case true:alert("true");break;
      case null:alert("null");break;
      case undefined:alert("undefined");break;

    }
    var i=2;
    while(i<=100){
      a+=i;
      i++;
    }
    alert(a);

    for(var oo=1;oo<100;oo++){
      a+=oo;
    }

    document.write("<table  align='center'>")
    var w=0;
    for(var j=1;j<=9;j++)
    {
      document.write("<tr>");
      for(var k=1;k<=j;k++){
        document.write("<td>")
        document.write(i+"*"+j+"="+(k*j)+"&nbsp;$nbsp;$nbsp;");
        document.write("</td>");
      }
      document.write("</tr>");
    }
    alert(a)
  </script>