js实现C#的StringBuilder效果完整实例

/*
  ##################### DO NOT MODIFY THIS HEADER #####################
  # Title: StringBuilder Class                    #
  # Description: Simulates the C# StringBuilder Class in Javascript. #
  # Author: Adam Smith                        #
  # Email: ibulwark@hotmail.com                    #
  # Date: November 12, 2006                      #
  #####################################################################
*/
// Simulates the C# StringBuilder Class in Javascript.
// Parameter["stringToAdd"] - The string to add. 
StringBuilder = function(stringToAdd)
{  
  var h = new Array();
  if(stringToAdd){h[0] = stringToAdd;} 
  this.Append = Append;
  this.AppendLine = AppendLine;
  this.ToString = ToString;
  this.Clear = Clear;
  this.Length = Length;
  this.Replace = Replace;
  this.Remove = Remove;
  this.Insert = Insert;
  this.GetType = GetType;   
  // Appends the string representation of a specified object to the end of this instance.
  // Parameter["stringToAppend"] - The string to append. 
  function Append(stringToAppend)
  {
    h[h.length] = stringToAppend;
  } 
  // Appends the string representation of a specified object to the end of this instance with a carriage return and line feed.
  // Parameter["stringToAppend"] - The string to append. 
  function AppendLine(stringToAppend)
  {
    h[h.length] = stringToAppend;
    h[h.length] = "\r\n";
  } 
  // Converts a StringBuilder to a String.
  function ToString()
  {
    if(!h){ return ""; }
    if(h.length<2){ return (h[0])?h[0]:""; }
    var a = h.join('');
    h = new Array();
    h[0] = a;
    return a;
  }
  // Clears the StringBuilder
  function Clear()
  {
    h = new Array();
  }
  // Gets the StringBuilder Length
  function Length()
  {
    if(!h){return 0;}
    if(h.length<2){ return (h[0])?h[0].length:0; }
    var a = h.join('');
    h = new Array();
    h[0] = a;
    return a.length;
  }
  // Replaces all occurrences of a specified character or string in this instance with another specified character or string.
  // Parameter["oldValue"] - The string to replace. 
  // Parameter["newValue"] - The string that replaces oldValue. 
  // Parameter["caseSensitive"] - True or false for case replace.
  // Return Value - A reference to this instance with all instances of oldValue replaced by newValue.
  function Replace(oldValue, newValue, caseSensitive)
  {
    var r = new RegExp(oldValue,(caseSensitive==true)?'g':'gi');
    var b = h.join('').replace(r, newValue);
    h = new Array();
    h[0] = b;
    return this;
  }
  // Removes the specified range of characters from this instance.
  // Parameter["startIndex"] - The position where removal begins. 
  // Parameter["length"] - The number of characters to remove.
  // Return Value - A reference to this instance after the excise operation has occurred.
  function Remove(startIndex, length)
  {    
    var s = h.join('');
    h = new Array();
    if(startIndex<1){h[0]=s.substring(length, s.length);}
    if(startIndex>s.length){h[0]=s;}
    else
    {
      h[0]=s.substring(0, startIndex); 
      h[1]=s.substring(startIndex+length, s.length);
    }
    return this;
  }
  // Inserts the string representation of a specified object into this instance at a specified character position.
  // Parameter["index"] - The position at which to insert.
  // Parameter["value"] - The string to insert. 
  // Return Value - A reference to this instance after the insert operation has occurred.
  function Insert(index, value)
  {
    var s = h.join('');
    h = new Array();
    if(index<1){h[0]=value; h[1]=s;}
    if(index>=s.length){h[0]=s; h[1]=value;}
    else
    {
      h[0]=s.substring(0, index); 
      h[1]=value; 
      h[2]=s.substring(index, s.length);
    }
    return this;
  }
  // Gets the type
  function GetType()
  {
    return "StringBuilder";
  }
};