JavaScript实现彩虹文字效果代码_JavaScript

JavaScript实现彩虹文字效果代码
<!-- Experiments with text   vegaseat   6/15/2002 -->
<!-- hexnumbers  -->
<HTML>
<HEAD>
<TITLE>Rainbow Text</TITLE>
<SCRIPT LANGUAGE="JavaScript">
<!-- Begin hide from old browsers
function createHexArray(n) 
{
  this.length = n;
  for (var i = 1; i <= n; i++)
    this[i] = i - 1;
  this[11] = "A";
  this[12] = "B";
  this[13] = "C";
  this[14] = "D";
  this[15] = "E";
  this[16] = "F";
  return this;
}
hx = new createHexArray(16);
function convertToHex(x) 
{
  if (x < 17) 
    x = 16;
	
  var high = x / 16;
  var s = high+"";
  
  s = s.substring(0, 2);
  high = parseInt(s, 10);
  
  var left = hx[high + 1];
  var low = x - high * 16;
  if (low < 1) 
    low = 1;
  s = low + "";
  s = s.substring(0, 2);
  low = parseInt(s, 10);
  
  var right = hx[low + 1];
  var string = left + "" + right;
  return string;
}
function makeRainbow(text) 
{
  text = text.substring(0, text.length);
  color_d1 = 255;
  mul = color_d1 / text.length;
  for(var i = 0; i < text.length; i++) {
    color_d1 = 255*Math.sin(i / (text.length / 3));
    color_h1 = convertToHex(color_d1);
    color_d2 = mul * i;
    color_h2 = convertToHex(color_d2);
    k = text.length;
    j = k - i;
    if (j < 0) 
	  j = 0;
    color_d3 = mul * j;
    color_h3 = convertToHex(color_d3);
    document.write("<FONT COLOR=\"#" + color_h3 + color_h1 + color_h2 + "\">" + text.substring(i, i + 1) + "</FONT>");
  }
}
// End  hide from old browsers -->
</script>
</HEAD>
<body bgcolor="#FFFFCC">
<center>
<strong>
<font size=6>
<script>
<!--
// change to your own text ...
makeRainbow("Welcome to Boulder City Nevada");
document.write("<br>");
makeRainbow("The best dam city in the USA");
// -->
</script>
</font>
</strong>
</center>
</body>
</html>