我很好

好的啊

<script> var divs = document.getElementsByTagName("div"); for (var i = 0; i < divs.length; i++) { divs[i].style.backgroundColor = "red"; } var ps = document.getElementsByTagName("p"); for (var j = 0; j < ps.length; j++) { ps[j].style.backgroundColor = "red"; } </script> 

我很好

好的啊

<script> function getTagname(tagName) { return document.getElementsByTagName(tagName); }

  function setStyle(arr) {
    for (var i = 0; i < arr.length; i++) {
      arr[i].style.backgroundColor = "red";
    }
  }

  var divs = getTagname("div");
  setStyle(divs);
  var ps = getTagname("p");
  setStyle(ps);
</script>
copy