String and StringBuffer Implementation - which is fast

All,

 

    I came across some interesting fact on String and String Buffer. We know that String concatination internaly uses StringBuffer to do the concatination operation, and thinking about this we do concatination as mentioned below: 

        String str=a+b; a and b is string objects.

 

    java compiler compiles above code in this fashion:

 

        String str=(new StringBuffer()).append(a).append(b).toString());

 

    Above code creates two objects, and as you must be knowing that java maintains the string data in char array which is also an object so +1 more object. So in total 3 objects gets created for one concatination operation. Please note that object creation is one of the costiliest operation in java.

 

    I created one test program just to see the performance difference and results were dramatic... i ran both loop in same program 1 lakhs times. See the time difference... So based on below result i would recommend please start using StringBuffer.append whenever you are doing any concatination operation in java...

 

    time taken by string: 78080 (ms)
    time taken by String buffer: 31 (ms)

 

 

 

 

 

 

 

 

How to identify the YUI version

Hi all,

Steps for identifying YUI version:

1. Open the YUIInclude.js (or respective YUI related JS you have used).
2. Search for the string ‘YAHOO.register(’.
3. This is a JS function where you pass the version number. Check its arguments for your YUI version.

NOTE: If you are using YUI version less than 2.8, please upgrade it to 2.8. This will not require any code changes other than JS and CSS file change. Do a thorough testing of your application functionality after upgrading.

Thanks.