Json字符串转换为JS对象的高效方法实例

  parseJSON: function( data ) {
  if ( typeof data !== "string" || !data ) {
   return null;
  }

  // Make sure leading/trailing whitespace is removed (IE can't handle it)
  data = jQuery.trim( data );

  // Make sure the incoming data is actual JSON
  // Logic borrowed from http://json.org/json2.js
  if ( /^[/],:{}/s]*$/.test(data.replace(///(?:["////bfnrt]|u[0-9a-fA-F]{4})/g, "@")
   .replace(/"[^"///n/r]*"|true|false|null|-?/d+(?:/./d*)?(?:[eE][+/-]?/d+)?/g, "]")
   .replace(/(?:^|:|,)(?:/s*/[)+/g, "")) ) {

   // Try to use the native JSON parser first
   return window.JSON && window.JSON.parse ?
    window.JSON.parse( data ) :
    (new Function("return " + data))();

  } else {
   jQuery.error( "Invalid JSON: " + data );
  }
 }

(new Function("return " + data))();

var jsonStr ="{";
for(var i=0;i<10000;i++){
 jsonStr+="a"+i+":"+i+","
}
jsonStr = jsonStr.substring(0,jsonStr.length-1);
jsonStr+="}";

var date = new Date();
var start = date.getTime()
//var boj = (new Function("return "+jsonStr ))();
var boj = eval("("+jsonStr+")");
var date1 = new Date();
console.info(date1.getTime()-start);