성능과 튜닝 String Performance: Getting Good Performance from Internet Explorer (IE7)

Conclusion : 

the performance of the “+=” operator was actually better in Internet Explorer 7 than pushing fragments into an array and joining them.

<IE7에서 문자열 조작은 Array 방식보다 "+=" 연산자가 효율이 더 좋다>

Sample : 

foreach(xmlElement in allXmlElements) {
  var jsonObject = {};
  jsonObject["firstName"] = xmlElement.getValueOf("firstName");
  jsonObject["lastName"] = xmlElement.getValueOf("lastName");
  ...
  processObject(jsonObject)
}

And the pseudo code for JSON:

var allJsonObjects = eval(jsonObjectsAsString);
foreach(jsonObject in allJsonObjects) {
  processObject(jsonObject);
}

processObject itself is simply concatenating the individual properties of the JSON Object to a global string variable:

globalString += jsonObject.firstName + " " + jsonObject.lastName + ...