SOURCE

<button onclick="myFunction()">
  生成
</button>
<p id="demo">
</p>
<script>
  function myFunction() {
    var i, j, k;
    var w = "";
    for (i = 1; i <= 9; i++) {
      //document.getElementById("demo").write("<br>");
      for (j = 1; j <= i; j++) 
      {
        k=i*j;
        w = w + i + "*" + j + "=" + k + "  ";
        document.getElementById("demo").innerHTML = w;
      }
      w = w + "<br>";
    }
  }
</script>