Coding Blog

I came across with this expression, button.enabled = !!enable !! is just a double not . This is just obscure.

HTML5 has a bunch of cool APIs. In one of my previous posts, I have written a simple demonstration of the Web Storage JavaScript API. In this post I will be showing another demonstration, the Web SQL Database JavaScript API. What is so fascinating about these APIs is they are “crash-safe.” Now you can lessen the load of your web servers and perform SQL tasks like, sorting, joining, etc. on the client side. Click [here] for the demonstration.

Let us say you have a list and you want to remove items while iterating through it if a certain condition satisfies. for (Object object : listOfObjects) { if (isConditionSatisfied) { listOfObjects.remove(object); } } What is wrong with this code above? Try it and you will get this, Exception in thread "main" java.util.ConcurrentModificationException You might want to do this instead, Iterator<Object> iterator = listOfObjects.iterator(); while (iterator.hasNext()) { Object object = iterator.next(); if (isConditionSatisfied) { iterator.remove(); } } Have a nice day.

Here is a simple demonstration of HTML5’s Web Storage. The code is quite straightforward. One thing to experiment is after entering any string and hitting save, try closing the browser entirely and opening it again visiting the same page to see if the data persisted. Click [here] for the demonstration.

It has been a while since I have written something about Javascript. You need to copy and paste this to your browser’s address bar to see how it works. javascript:R=0; x1=.1; y1=.05; x2=.25; y2=.24; x3=1.6; y3=.24; x4=300; y4=200; x5=300; y5=200; DI=document.getElementsByTagName("a"); DIL=DI.length; function A(){for(i=0; i-DIL; i++){DIS=DI[ i ].style; DIS.position='absolute'; DIS.left=(Math.sin(R*x1+i*x2+x3)*x4+x5)+"px"; DIS.top= (Math.cos(R*y1+i*y2+y3)*y4+y5)+"px"}R++}setInterval('A()',50); void(0); Enjoy!

Which one is faster? a == null or null == a ? This is the method of the former. public static boolean firstNullCheck(Object a) { if (a == null) { return true; } return false; } and the method of the latter. public static boolean secondNullCheck(Object a) { if (null == a) { return true; } return false; } Here’s the disassembly of the former. public static boolean firstNullCheck(java.lang.Object); Code: 0: aload_0 1: ifnonnull 6 4: iconst_1 5: ireturn 6: iconst_0 7: ireturn and the disassembly of the latter. public static boolean secondNullCheck(java.lang.Object); Code: 0: aconst_null 1: aload_0 2: if_acmpne 7 5: iconst_1 6: ireturn 7: iconst_0 8: ireturn The former saves you a bytecode. Anyone who can explain further since I am not sure whether if_acmpne is faster than ifnonnull ?

If you do not want your search queries to be compromised, use Google SSL . However, there is one thing I discovered though, if you click on a cached link, it’s not encrypted, it goes back to HTTP from HTTPS making the protected search useless. Just be aware.

Why are daily meetings important? Yes I know what you are thinking, to check if the schedule is on target, to spot showstoppers, roadblocks and whatnots. But aside from those, there are things that make daily meetings rewarding. Let’s face it, some people (including me) find it hard oftentimes to achieve a certain level of focus at work especially when multitasking is inevitable. Meetings will remind us of our commitments infront of our peers. Since most of us will be ashamed of not making any progress, it will trigger ourselves to do something about it. In my opinion, having daily meetings typically before the shift starts will help a lot of peers suffering from bad habits - procrastination. It is one way of invigorating those who have not found their way out yet. “Keep each other in the zone, what are teammates for?”

A very simple party, KFC Bucket, 1 Black Forest Cake. Thank you God for another blessed year.

There is great power here. I know most of you are not taking advantage of these operators. 1. + (plus) - this will yield search results ordered by the number of occurrences of the specified word 2. - (dash) - this will yield search results that do not contain the specified word 3. " " (double quotes) - this will yield search results containing the exact word specified 4. . (dot) - is a wildcard representing a single character 5. * (asterisk) - is a wildcard representing a single word 6. | - traditional OR operator 7. site: - search within a specified domain 8. intitle: - this will search for the 1st specified word in page titles and the 2nd specified word in the text 9. allintitle: - this will search for texts in page titles only 10. inurl: - this will search for URLs containing the specified word 11. allinurl: - this will search for texts in URLs only 12. filetype: - this will search for texts containing files of the specified extension and the specified word 1...

These operators will give you more precise search results. 1. from: - mails from the name of the sender 2. to: - mails sent/to be sent to to the recipient 3. subject: - search mails containing the specified words in the subject 4. OR - traditional OR operator 5. - (dash or hyphen) - exclude messages containing the specified words 6. label: - search messages by label 7. has:attachment - search mails with attachments 8. filename: - search mails by filename of the attachments 9. " " (double quotes) - traditional operator for filtering exact specified words 10. () - used for grouping search expressions 11. in:anywhere - search for mails anywhere in your account 12. in:inbox - search for mails in your inbox 13. in:trash - search for mails in your trash folder 14. in:spam - search for mails in your spam folder 15. is:starred - search for starred mails 16. is:unread - search for unread mails 17. is:read - search for read mails 18. cc: - search mails that were ca...

In Java, multibyte data items or streams are stored in big endian order. Using Java to write bytes directly to the wire will require byte-order transformation if the recipient talks in little endian. The same is true if you are reading directly from the wire from a sender who talks in little endian. If you are using a byte array wrapped in ByteBuffer, byte[] data = new byte[] { 12, 19, 83, 05, -05, 55, -55 }; ByteBuffer byteBuffer = ByteBuffer.wrap(data); Transforming from big endian to little endian is easy, byteBuffer.order(java.nio.ByteOrder.LITTLE_ENDIAN); If you are unsure of the endianness of the underlying platform, just invoke the native order method. java.nio.ByteOrder.nativeOrder(); Aside from streams, operands in classes that are above 1 byte in size are in big endian order.

Putting your keyboard where your brain is means that you are a candidate for repetitive strain injury . You should check out Workrave now. Workrave is a free software available for Windows and *Nix users. If you are working on a Debian-based system, sudo apt-get install workrave Windows users, download [here] .

Lambda expressions are just (anonymous) functions. f(x) = x can be expressed as x→x f(x, y) = x*x + y*y can be expressed as x, y→x*x + y*y In simple Java terms, 1. Return an int 23 with a void argument int j = { => 23 }.invoke(); 2. Closure with 1 argument, convert 23 kilograms to pounds double j = { double kilograms => kilograms*2.2D }.invoke(23); 3. Closure with 2 arguments, get the sum of the 2 squares int squareSum = { int x, int y => (x*x) + (y*y) }.invoke(2,3); 4. Closure returning an instance and invoking an instance method { new RocketLauncher() }.invoke().fire(); Every time a closure is created at compile time, an interface is automatically created for each expression having an invoke method with a signature depending on the number of arguments, then an anonymous subclass of this interface is constructed. Enjoy!

Happy New Year!