JavaScript中JSON与字符串互转的实现方法

jsonToString: function(obj){ 
    var THIS = this;  
    switch(typeof(obj)){ 
      case 'string': 
        return '"' + obj.replace(/(["\\])/g, '\\$1') + '"'; 
      case 'array': 
        return '[' + obj.map(THIS.jsonToString).join(',') + ']'; 
      case 'object': 
         if(obj instanceof Array){ 
          var strArr = []; 
          var len = obj.length; 
          for(var i=0; i<len; i++){ 
            strArr.push(THIS.jsonToString(obj[i])); 
          } 
          return '[' + strArr.join(',') + ']'; 
        }else if(obj==null){ 
          return 'null'; 
 
        }else{ 
          var string = []; 
          for (var property in obj) string.push(THIS.jsonToString(property) + ':' + THIS.jsonToString(obj[property])); 
          return '{' + string.join(',') + '}'; 
        } 
      case 'number': 
        return obj; 
      case false: 
        return obj; 
    } 
 }, 

stringToJSON: function(obj){ 
    return eval('(' + obj + ')'); 
},