JavaScript StringBuffer like java StringBuffer object

function StringBuffer()
{
  this.buffer = [];
}

StringBuffer.prototype.append = function(string) 
{ 
  this.buffer.push(string); 
  return this; 
} 

StringBuffer.prototype.toString = function()
{ 
  return this.buffer.join(""); 
}

Usage: var s = new StringBuffer(); s.append("Hello, ").append(" World!"); alert(s.toString());