Tuesday, September 11, 2012

Quick Sort in JAVA

Quick Sort is one of the fastest sorting algorithms.
Here is the code snippet for Java.

public static int divide(int array[], int left, int right)
        int i = left, j = right;
        int tmp;
        int pivot = array[(left + right) / 2];
        while (i <= j) {
            while (array[i] < pivot)
            while (array[j] > pivot)
            if (i <= j) {
                tmp = array[i];
                array[i] = array[j];
                array[j] = tmp;
        return i;
    public static void q_srt(int arr[], int left, int right) {
        int i = divide(arr, left, right);
        if (left < i - 1)
            q_srt(arr, left, i - 1);
        if (i < right)
            q_srt(arr, i, right);
     * @param args the command line arguments
    public static void main(String[] args) {
        // TODO code application logic here
        int []sample = {13,21,36,0,32,54,1,3};
        for(int x=0;x<sample.length;x++){
        System.out.println("\n-=Sorted Array=-");
        for(int x=0;x<sample.length;x++){

Methods to read excel files in C#

Useful C# methods in order to read cell values in excel.
Remember to add a .NET reference for Microsoft.Office.Interop.Excel and use it in your program via the statement using Microsoft.Office.Interop.Excel;

private static Microsoft.Office.Interop.Excel.ApplicationClass appExcel;
private static Workbook newWorkbook = null;
private static _Worksheet objsheet = null;

Method to initialize excel connection:
        static void excel_init(String path)
            appExcel = new Microsoft.Office.Interop.Excel.ApplicationClass();

            if (System.IO.File.Exists(path))
                // then go and load this into excel
                newWorkbook = appExcel.Workbooks.Open(path, true, true);
                objsheet = (_Worksheet)appExcel.ActiveWorkbook.ActiveSheet;
                MessageBox.Show("Unable to open file!");
                appExcel = null;

Method to read a cell's value:
        static string excel_getValue(string cellname)
            string value = string.Empty;
                value = objsheet.get_Range(cellname).get_Value().ToString();
                value = "";

            return value;

Method to safely close excel connection:
        static void excel_close()
            if (appExcel != null)
                    appExcel = null;
                    objsheet = null;
                catch (Exception ex)
                    appExcel = null;
                    MessageBox.Show("Unable to release the Object " + ex.ToString());

To use it in your program, you need to initialize the excel connection first via this method:
make sure that your slash \ are double slashes \\. E.g. C:\\excel_file.xls

To read a cell value:
excel_getValue("A1"); this will return the value of the cell.

Safely close the connection with
excel_close(); to prevent memory problems.

Thanks for reading! I hope you gain additional knowledge.

If you have questions and or problems using it, please comment on this article.


First C++ Program

Start your preferred IDE for C++ and create a new Console Application or a new project. Name it as you desired. For Visual C++ and Visual Studio, Create a new Project->Other Languages->Visual C++->Win32->Win32 Console Application. Next Next...Check the check box for empty project.

For Visual C++/Visual Studio,
  1. In the Solution Explorer tab, right click the source files (folder icon), add->new item
  2. Select C++ File, name it main or a name that you desire.
Try to code this and run your program. For Visual C++ or Visual Studio Pressing F5 will run the program.
Please post your comments if you have problems doing it. Thanks!

#include <iostream>

using namespace std;

int main()
    cout<<"Hello World!";
    return 0;

#include <iostream> - #include is a preprocessor directive, #include <iostream> tells the compiler to include the file iostream that contains functions/method declarations for standard input/output that will be used like cout (System.out.println in JAVA).

using namespace std; - the elements/functions/methods in the iostream are declared in a namespace with the namespace std. To access its functionality we will use this entities. This line is a frequently used line for Console apps in C++.

int main() - like in JAVA, it is the starting point of a program. Open curly brace { indicates the beginning of the function main() and Close curly brace indicated the end of the function main();

cout<<"Hello World!"; - cout is the standard output stream in C++, it is declared in the iostream. << is an insertion operator telling that the string "Hello World!" will be the output. cout is like System.out.print in JAVA.

semicolon ; - it is a very important character in C++ in order to end a command statement. This is a common error among programmers.

cin.get(); - is a function to accept a character input from the user. This is used here so that the console app will not close immediately after displaying Hello World!.

return 0; - the method main will return a value of 0. This is a common use to indicate a successful program exit or execution.

If you have problems, please comment. Thanks!

Next: C++ Variables

Getting Started with C++ (cplusplus)

In this series of tutorials, you will learn the basic programming of C++ language. You may also return back from the table of contents to search topics that you want to learn.
You will learn by examples and simple explanations. This will be a quick tutorial for fast learners.

Setting up the IDE:
You may use the following IDE's for this tutorial:
  1. Visual Studio or Visual C++ only, you may download at here
  2. Code Blocks at http://www.codeblocks.org/
  3. NetBeans with C++ at http://netbeans.org/downloads/index.html
These are some of the popular easy to install and use Integrated software development tools. You may refer to their documentations if you have problem installing or ask us by posting your comments.

In these tutorials, I will use Visual Studio 2010 Ultimate, but note that you can also use other IDE's.

Comments/Suggestions/Questions are well accepted.

Thank you very much,

Next: First C++ program

Monday, September 10, 2012

Code Doppler Programming Tutorials: Learn JAVA

Code Doppler Programming Tutorials: Learn JAVA: You will learn JAVA language in the quickest possible way! A series of tutorial will teach you the Basic of JAVA programming and one of it...

Wednesday, September 5, 2012

Welcome to Codedoppler

Code Doppler is a newborn community for newbie to professional developers in JAVA and C++ programming languages. Our purpose is to provide free tutorials, hints, tips and sample source codes. These tutorials will be the quickest tutorials for newbie programmers that wants to learn programming the quickest way! Also, we will try our best to answer all your questions regarding programming! Thank you very much, Administrators