zParacha — Effective Programming Tips

Insertion Sort Algorithm In Java

Mon, 22 Jan 2018 00:00:00 GMT

Insertion sort is a simple algorithm. Insertion sort logic works as follows: To insert an element in an already existing set, we make room for the new item

Selection Sort Algorithm in Java

Sun, 21 Jan 2018 00:00:00 GMT

Selection sort is one of the simplest sorting algorithms. It is easy to implement but it is not very efficient. The algorithm divides the input list into two pa

How to calculate the height of a Non-Binary Tree

Mon, 01 Jan 2018 00:00:00 GMT

Computing the height of a tree in Computer Science is very common. Most of the examples and online discussions talk about computing the height of a Binary Tree.

Easiest way to calculate elapsed time in Java

Sat, 23 Dec 2017 00:00:00 GMT

Quite often in our day-to-day programming, we need to compute how long a specific portion of the code takes to complete. For e.g; you might want to check how lo

Java Regular Expression to Validate Social Security Number (SSN)

Fri, 08 Dec 2017 00:00:00 GMT

Here is a utility method to check if a given String is a valid Social Security number using Java Regular Expression.

Java Regular Expression to check if a String is a numeric value

Mon, 04 Dec 2017 00:00:00 GMT

Here is another method from my String utility class. This method uses a regular expression to check if a String is a numeric value. Look at the code, then read

How to delete Workspace from Eclipse Launcher Selection

Sun, 03 Dec 2017 00:00:00 GMT

Launch Eclipse Click on Recent Workspaces Eclipse will list all previously used workspaces Right click on the workspace name that you want to remove Click on Re

How to generate random alpha numeric String in Java

Fri, 01 Dec 2017 00:00:00 GMT

Following code is an example of generating a random alpha-numeric string using Java Random class. It is designed to generate random String of varying length bas

Java Scanner’s unexpected behavior following nextInt or nextDouble call

Tue, 28 Nov 2017 00:00:00 GMT

Scanner is a utility class that provides methods to read command-line input. It is a very useful class, but you need to be aware of its unexpected behavior whil

How to compare Java Strings correctly

Sat, 25 Nov 2017 00:00:00 GMT

One of the most common bugs I’ve seen in Java programs is the use of the == operator to compare two String objects. Most of the time the result may be acc

Java RegEx to validate Gmail address

Fri, 24 Nov 2017 00:00:00 GMT

I’ve written about Java regular expression to validate email addresses before. Today I am sharing another Java regex to validate Gmail address. It

How to find largest and smallest numbers from input in Java

Thu, 23 Nov 2017 00:00:00 GMT

Following simple Java program shows how to read input values and then print smallest and largest values. It reads the input from standard input using Scanner an

Array Bubble Sort in Java

Wed, 22 Nov 2017 00:00:00 GMT

Although Java’s Arrays class has a built-in method to sort an array, it is important for good Java developers to know how to sort an array on their own. B

Top 10 Eclipse Keyboard shortcuts for Java developers

Thu, 08 Sep 2016 00:00:00 GMT

Here is a list of 10 commonly used Eclipse shortcuts for Java developers. Ctrl + Shift + T: Open a type (e.g.; a class, an interface) without browsing through l

How to validate Date using Javascript Regular Expression

Mon, 03 Dec 2012 00:00:00 GMT

Here is a simple Javascript function to validate a date in US format.

How to redirect homepage in Joomla

Tue, 08 Nov 2011 00:00:00 GMT

Joomla is a wonderful platform to publish websites. With readily available templates you can have your website up and running in no time. Sometimes though you m

Sort numbers in Java to find minimum and maximum values without using Array

Fri, 21 May 2010 00:00:00 GMT

Recently a reader contacted me with a question about sorting numbers in Java. After sorting the number the program then needs to print the largest and smallest

Java String comparison. The difference between == and equals().

Tue, 23 Feb 2010 00:00:00 GMT

Many Java beginners find it difficult to differentiate between == operator and the “equals()” method when comparing String variables in Java. They a

An HTML element you don’t want to omit.

Wed, 17 Feb 2010 00:00:00 GMT

As web developers we have the tendency to blame web browsers for inconsistencies and for not displaying the pages as designed. Most of the time the blame is jus

Why you should stop using onload method.

Mon, 01 Feb 2010 00:00:00 GMT

It is amazing that many web developers still use onload method embedded in the BODY tag, like

How to remember CSS Shorthand properties

Mon, 01 Feb 2010 00:00:00 GMT

Using margin or padding properties of CSS in the following syntax is straight forward. { padding-top:5px; padding-right:12px; padding-bottom: 15px; padding-left

Five free tools to choose perfect colors for your website.

Fri, 29 Jan 2010 00:00:00 GMT

Color coordination plays a big role in the look and feel of a website. An appealing color scheme is an important prerequisite for eye-catching web design. Dull

How to position HTML element in the center using CSS.

Tue, 19 Jan 2010 00:00:00 GMT

Positioning text in the center of an element is easily done using text-align:center property. But how do you position an entire element, for e.g; a div or an im

Reset CSS: A simple solution to browsers’ inconsistencies.

Sun, 10 Jan 2010 00:00:00 GMT

One of the challenges web designers face is to get various web browsers render their web pages in a consistent manner. The reason is every browser assigns sligh

How to convert an ArrayList to array in Java

Wed, 25 Nov 2009 00:00:00 GMT

Today, I will share a very basic Java program that converts an ArrayList to an array. For most Java developers this is a routine task, but many newcomers to Jav

How to validate date using Java regular expression

Tue, 17 Nov 2009 00:00:00 GMT

My earlier post on how to validate email address, SSN and phone number validation using Java regex still attracts a lot of visitors. Today I realized that anoth

How to write to properties file in Java

Mon, 09 Nov 2009 00:00:00 GMT

One of most visited posts on this blog is How to read properties file in Java. In that post I explained how you can read from a properties file. But many people

Best way to check if a Java String is a number.

Mon, 02 Nov 2009 00:00:00 GMT

An example on how to validate if a String variable in Java has all numeric digits.

Nine Must Have JavaScript Tools For Every Web Developer

Thu, 15 Oct 2009 00:00:00 GMT

Almost all major web development projects include some javascript. Developing Javascript may be easy for some but working around various browsers’ incompa

How to determine smallest and largest number in Java

Thu, 01 Oct 2009 00:00:00 GMT

A couple of weeks ago a reader asked me for a Java program to read command-line input from the user and then display the smallest value the user has entered. He

New features coming to Java 7

Sat, 05 Sep 2009 00:00:00 GMT

Joseph Darcy, the lead of Project Coin, formally announced the approved changes to the Java language to be included in JDK 7. Although there was no major chang

How to search for a string in a file using Java regular expression.

Tue, 28 Jul 2009 00:00:00 GMT

If you need to search for a phrase or a string in a text file Java regular expression is the easiest way to accomplish this task. Here is a simple example that

How to remove (delete) Eclipse workspace from the dropdown list.

Sat, 30 May 2009 00:00:00 GMT

Eclipse is my favorite Java IDE. To manage projects Eclipse uses ‘Workspaces’. Workspace is basically a folder on your disk where your project files

Top four free programs to capture screenshot

Thu, 16 Apr 2009 00:00:00 GMT

For most web developers, programmers and bloggers taking screenshots is quite a common task. Sometimes you need the screenshot for your next post or article or

Ultimate Java Regular Expression to validate any email address.

Sun, 01 Feb 2009 00:00:00 GMT

My post about Java regular expression gets a lot of hits daily. Someone commented that the regular expression I included in that post does not block certain inv

How to read properties file in a Spring Application.

Fri, 23 Jan 2009 00:00:00 GMT

If you need to read the properties file in your Spring application all you need is to configure a PropertyPlaceholderConfigurer bean in your application context

How to display RSS feed on your website.

Tue, 20 Jan 2009 00:00:00 GMT

Image credit:Kyle Wegner OK, admit this. You have a nice-looking website. The color and the graphics look pleasing to visiting eyes. But you do not get a lot of

How to configure multiple handlers in a Spring MVC web application

Sun, 04 Jan 2009 00:00:00 GMT

In Spring MVC, DispatcherServlet relies on handler mapping to determine which controller the request should be sent to. All handler mapping classes in Spring im

DropBox rings in new year with sleek new web interface.

Wed, 31 Dec 2008 00:00:00 GMT

One of the most popular file-sharing applications DropBox has a new and improved web interface. It now offers a new and improved navigation. They have also tran

Achieve more by typing less, use PhraseExpress.

Mon, 29 Dec 2008 00:00:00 GMT

If you do a lot of repetitive typing, you may want to consider using PhraseExpress. This recently updated text-replacement application can save you a lot of key

How to remove Ctrl-M (^M) from Unix files?

Tue, 09 Dec 2008 00:00:00 GMT

Sometimes when you upload or FTP files from a Windows system to a UNIX box you will see ^M at the end of each line. ^M is the UNIX equivalent of DOS line break.

ColorPix. Free utility to determine the hex code of any color.

Mon, 24 Nov 2008 00:00:00 GMT

Ever wanted to use a shade of color you found on a website or an image on your own website? You can find out the text color, background color etc. by looking at

Extract substring from end of a Java String

Thu, 07 Aug 2008 00:00:00 GMT

Today I’ll show you how to extract last few characters (a substring) from a string in Java. Here is the code to do this.

How to add external jar files to Maven project POM

Sat, 19 Jul 2008 00:00:00 GMT

Maven has made compiling Java projects almost an effortless job. You no longer need to worry about placing all the required class files in your classpath. All y

Print large string in PL/SQL.

Tue, 01 Jul 2008 00:00:00 GMT

For PL/SQL developers put_line is a quite useful method. I use it for logging purposes. Recently I found out that the method has an annoying limitation. You can

Import static elements for more readable Java code

Wed, 21 May 2008 00:00:00 GMT

One of the welcome additions to Java language in Java 5 release is the static import declaration. static import works in the same way as traditional import decl

Test your Java skills.

Tue, 13 May 2008 00:00:00 GMT

Even with many years of experience with programming in Java one cannot claim that he or she has mastered the language. What I found out with experience is that

Three ways to find minimum and maximum values in a Java array of primitive types.

Sun, 13 Apr 2008 00:00:00 GMT

In Java you can find maximum or minimum value in a numeric array by looping through the array. Here is the code to do that. public static int getMaxValue(int[]

How to read properties file in Java.

Tue, 08 Apr 2008 00:00:00 GMT

Reading properties file in Java is much easier than you might have thought. Following example illustrates one simple way of reading properties from a properties

Simple JavaScript Regular Expression to Validate U.S Phone Numbers

Thu, 28 Feb 2008 00:00:00 GMT

Image credit: aussiegall Continuing with our JavaScript regular expression series today we will discuss JavaScript regular expression to validate U.S phone numb

Validate Zip code using JavaScript Regular expression

Mon, 18 Feb 2008 00:00:00 GMT

Continuing with my series of JavaScript regular expression today we will see how easy it is to validate zip code using regular expression in JavaScript. Previou

How to validate Social Security Number (SSN) using JavaScript Regular Expressions

Fri, 15 Feb 2008 00:00:00 GMT

When I wrote the JS regular expression article last week I had no idea that it will attract so many visitors. Not only did so many people read this post, many m

Validate email address using JavaScript regular expression

Thu, 07 Feb 2008 00:00:00 GMT

Last month I wrote about regular expressions in Java, today I’ll show you how to use regular expression in JavaScript to validate email address. Here is t

Set focus on the first text field of HTML form.

Wed, 30 Jan 2008 00:00:00 GMT

A HTML form is a very good channel that you can offer to your visitors to contact you. An aesthetically appealing form encourages user to fill and submit it. It

How to validate email, SSN, phone number in Java using Regular expressions.

Thu, 10 Jan 2008 00:00:00 GMT

Regular Expressions offer a concise and powerful search-and-replace mechanism. They are patterns of characters used to perform a search, extract or replace oper

Java Utility for JDBC

Thu, 20 Dec 2007 00:00:00 GMT

Code re-usability is one of the many benefits of object oriented programming. For example, in Java if you need to perform email validation in different classes,

Make your stylesheet a work of art.

Sat, 08 Dec 2007 00:00:00 GMT

Jina Bolton at Vitamin.com has an excellent post for all CSS developers. She described how you can write well structured stylesheets which are more efficient an

Sort numbers in Javascript array

Wed, 05 Dec 2007 00:00:00 GMT

Sorting an array in Javascript is a snap. You create an array and then call sort() method on that array. The Javascript sort() method sorts an array in lexicogr

Compress JavaScript and CSS files to optimize website speed.

Thu, 22 Nov 2007 00:00:00 GMT

Referencing external JavaScript and/or CSS files from a web page considerably increases the load time. As a rule of thumb remember that each external file requi

Improve your JavaScript code.

Mon, 19 Nov 2007 00:00:00 GMT

Christian Heilmann compiled a list of seven rules for unobtrusive JavaScript. I think it is a must read for beginner JavaScript developers. Even if you are a hi

CSS Rounded Box Generator

Mon, 19 Nov 2007 00:00:00 GMT

A nice little tool to create rounded boxes for your website. You can choose the background color for your box. The tool will generate the CSS code and a sample

Creating Cross Browser Compatible CSS Text Shadows

Wed, 14 Nov 2007 00:00:00 GMT

Sometimes it is nice to jazz up your website by giving text some graphical looks without actually using images. The CSS2 text-shadow property allows you to crea

Display external RSS feeds on your website.

Mon, 12 Nov 2007 00:00:00 GMT

You have designed a beautiful website. But you still do not get a lot of loyal visitors. The problem may not be your design, it may be the static content that i

Dynamically Resize Text

Tue, 06 Nov 2007 00:00:00 GMT

CSS, combined with little JavaScript, offers great flexibility to web designers. For instance, let say you want to allow visitors to change text size on your we

Best free software

Sun, 04 Nov 2007 00:00:00 GMT

Thanks to Open source movement there are plenty of free software available for our day to day computing needs. Here is a partial list of my favorite software. M

Automatically Sort Vector Elements

Fri, 02 Nov 2007 00:00:00 GMT

Vector class in java.util package is very easy to use. You can add objects of any type in a vector. You don’t have to worry about declaring the size of th

#1 Programming Language – Java

Thu, 01 Nov 2007 00:00:00 GMT

According to TIOBE Programming Community Index Java is still the #1 programming language. TIOBE Index gives an indication of the popularity of a programming lan

Cascading Style Sheet Cheatsheet

Fri, 26 Oct 2007 00:00:00 GMT

If you need quick reference CSS guide, look no further. This CSS cheat sheet is a comprehensive list of all CSS properties. Accompanying brief explanation adds

Dynamically loading an external JavaScript or CSS file

Fri, 26 Oct 2007 00:00:00 GMT

A very good article explaining how to load JavaScript and CSS files asynchronously and on demand. Dynamically loading an external JavaScript or CSS file

AJAX Contact Form

Sun, 21 Oct 2007 00:00:00 GMT

Want to collect input from your web site’s visitors? Don’t have time or expertise to develop the contact form yourself? Don’t worry. Dustin Di