Javascript implements the color rgb and hexadecimal conversion method

The example in this article shows how Javascript can convert color rgb to hexadecimal. Share with you for your reference. The details are as follows:

Usage:

Color(12,34,56);
Color("#fff")
Color("#defdcd")

Implementation code:

// Color conversion 
var Color = function() {
  if (!(this instanceof Color)) {
   var color = new Color();
   color._init.apply(color, arguments);
   return color;
  }
  if (arguments.length) {
   this._init.apply(this, arguments);
  }
}
// Set up the get . set methods 
var methods = ["red", "green", "blue", "colorValue"];
var defineSetGetMethod = function(fn, methods) {
  var fnPrototype = fn.prototype;
  for (var i = 0; i < methods.length; i++) {
   var methodName = methods[i].charAt(0).toLocaleUpperCase() + methods[i].substring(1);
   fn.prototype['set' + methodName] = new Function("value", "this." + methods[i] + "= value;");
   fn.prototype['get' + methodName] = new Function("return this." + methods[i] + ";");
   fn.prototype['toString'] = new Function('return "rgb("+this.red+","+this.green+","+this.blue+")";');
  }
};
defineSetGetMethod(Color, methods);
// Extends the instance method of the function 
var extend = function(fn, option) {
  var fnPrototype = fn.prototype;
  for (var i in option) {
   fnPrototype[i] = option[i];
  }
};
extend(Color, {
  _init : function() {
   if (arguments.length == 3) {
    this.red = arguments[0];
    this.green = arguments[1];
    this.blue = arguments[2];
    this.getColorValue();
   } else {
    var colorValue = arguments[0].replace(/^\#{1}/, "");
    if (colorValue.length == 3) {
     colorValue = colorValue.replace(/(.)/g, '$1$1');
    }
    this.red = parseInt('0x' + colorValue.substring(0, 2), 16);
    this.green = parseInt('0x' + colorValue.substring(2, 4), 16);
    this.blue = parseInt('0x' + colorValue.substring(4), 16);
    this.colorValue = "#" + colorValue;
   }
  },
  getColorValue : function() {
   if (this.colorValue) {
    return this.colorValue;
   }
   var hR = this.red.toString(16);
   var hG = this.green.toString(16);
   var hB = this.blue.toString(16);
   return this.colorValue = "#" + (this.red < 16 ? ("0" + hR) : hR) + (this.green < 16 ? ("0" + hG) : hG) + (this.blue < 16 ? ("0" + hB) : hB);
  }
});

I hope this article is helpful to you in javascript programming.