Search Pattern in Java

Program to find a specific pattern from a given text or file is stated as below.



import java.io.*;

class srchPattern
{
  public static void main(String args[])
  {
    if(args.length == 0 || args.length == 1)
    {
      System.out.println("Insufficient arguments...");
      return;
    }

    File f = new File(args[1]);

    try
    {
      BufferedReader i = new BufferedReader(new FileReader(args[1]));

      String line;
      int ct = 0;

      if(f.exists() && f.isFile())
      {
        while((line = i.readLine()) != null)
        {
          if((line.indexOf(args[0])) != -1)
          {
            ct++;
          }
          System.out.println(line + " ");
        }

        if(ct == 0)
        {
          System.out.println("Pattern not Found");
        }
        else
        {
          System.out.println("Pattern found in the file...");
          System.out.println("Number of Occurances of the word " + args[0] + " in te file " + args[1] + " is " + ct);
        }
      }
    }
    catch(Exception e){}
  }
}

Word,character count in Java

Program  to count the number of occurrences of a word in a file is given as below:


import java.io.*;

class wordcnt
{
  public static void main(String args[])
  {
    int i = 0,cnt = 0;
    try
    {
      FileInputStream fin = new FileInputStream("d:/java/wordcnt.java");
      String word;
      char ch , charr[];
      charr = new char[100];
      String w = new String("word");
      while(( ch = (char)fin.read()) != -1)
      {
        if( ch != ' ' && ch != '\n')
        {
           charr[i] = ch ;
           i++;
        }
        else
        {
           word = new String(charr,0,i);
           if(word.equals(w))
              cnt++;   
           if( ch == '\n')
              System.out.println( word );
           else
              System.out.print( word + " ");
           i = 0;
        }
     };
     fin.close();
    }
    catch(Exception ie)
    {
    }
    System.out.println("\n\nWord Count : " + cnt);
  }
}

Copy file in Java

Program to copy a file content in java is as follows:

 import java.io.*;

class FileCopy
{
  public static void main(String args[]) throws IOException
  {
    FileInputStream fin = new FileInputStream("d:/java/stk.java");
    FileOutputStream fout = new FileOutputStream("d:/java/txtfile.txt");
    int b;

    while(true)
    {
      b = fin.read();
      if(b == -1)
      {
        break;
      }
      System.out.print((char)b);
      fout.write(b);
    }

    fin.close();
    fout.close();
  }
}

Polynomial operations in Java

Program for Ploynomial expression in java is as follows:


import java.lang.*;
import java.io.*;
class term
{
  int coeff,exp;
}
class poly
{
    term pl[] = new term[10];
    int n;
    poly()throws Exception
    {
        poly p[]=new poly[10];
        BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
        System.out.println("Enter the no. of terms: ");
        n=Integer.parseInt(br.readLine());
    }
    public void getPoly()throws Exception
    {
        poly p[]=new poly[10];
        BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
        System.out.println("Enter the base & exponent:");
        for(int i=0;i<n;i++)
        {
            p[i].coeff=Integer.parseInt(br.readLine());
            p[i].exp=Integer.parseInt(br.readLine());
        }
    }   
    public void putPoly()
    {
        poly p[]=new poly[10];
        System.out.println("Polynomial is : ");
        for(int i=0;i<n;i++)
        {
            System.out.println(" "+p[i].coeff+"x^"+p[i].exp);
        }
    }
    public void evalPoly()throws exception
    {
        poly p[]=new poly[10];
        BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
        int x,ans=0;
        System.out.println("Enter the value for x:");
         x=Integer.parseInt(br.readLine());   
        for(int i=0;i<n;i++)
        {
            ans=ans+p[i].coeff*pow(x,p[i].exp);
        }
        System.out.println("Ans : "+ans);
    }
    public static void main(String args[])throws Exception
    {
        poly p1=new poly();
        poly p2=new poly();
        p1.getPoly();
        p2.getPoly();
        p1.putPoly();
        p2.putPoly();
        p1.evalPoly();
       
    }   
}

Matrix in Java

Program for matrix in java is as follows:


import java.io.*;

class matrix
{
  int mat[][],r,c;

  matrix()
  {
     mat = new int[10][10];
  }
  public void getMat() throws Exception
  {
   // mat = new int[10][10];
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    System.out.println("\nEnter the Dim of the matrix : ");    
    r = Integer.parseInt(br.readLine());
    c = Integer.parseInt(br.readLine());

    System.out.println("\nEnter the matrix elements : ");    
    for(int i = 0 ; i < r ; i++)
    {
      for(int j = 0 ; j < c ; j++)
      {
        mat[i][j] = Integer.parseInt(br.readLine());
      }
    }
  }

  public void addMat(matrix m1,matrix m2)
  {
     r = m1.r;
     c = m1.c;

     for(int i = 0 ; i < r ; i++)
    {
       for(int j = 0 ; j < c ; j++)
       {
          mat[i][j] = m1.mat[i][j] + m2.mat[i][j];
       }
    }
  }

  public void putMat()
  {
    System.out.println("\nMatrix is : \n");
    for(int i = 0 ; i < r ; i++)
    {
      for(int j = 0 ; j < c ; j++)
      {
        System.out.print(" " + mat[i][j]);
      }
      System.out.println("");
    }
  }

  public static void main(String args[]) throws Exception
  {
    matrix m1 = new matrix();
    matrix m2 = new matrix();
    matrix m3 = new matrix();

    m1.getMat();
    m2.getMat();

    m1.putMat();
    m2.putMat();

    m3.addMat(m1,m2);
    m3.putMat();
  } 
}

Linear Search in Java

Below is simple program in java which shows the linear search.


import java.io.*;

class LinearSearch
{
  int ar[];
  int ele,n;

  public void setData() throws Exception
  {
     ar = new int[10];
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    System.out.println("Enter the size for array : ");    
    n = Integer.parseInt(br.readLine());

    System.out.println("Enter the data for array : ");    
    for(int i = 0 ; i < n ; i++)
    {
      ar[i] = Integer.parseInt(br.readLine());
    }
    
    System.out.println("Enter the data to be searched : ");
    ele = Integer.parseInt(br.readLine());
  }

  public void putData()
  {
    System.out.println("The array is : ");
    for(int i = 0 ; i < n ; i++)
    {
      System.out.println(" " + ar[i]);
    }
  }

  public void LinSrch()
  {
    int i;
   
    for(i = 0 ; i < n ; i++)
    {
      if(ar[i] == ele)
      {
        break;
      }
    }
    if(i == ar.length)
    {
      System.out.println("\nElement not found");
    }
    else
    {
      System.out.println("\nElement found at " + i);
    }
  }

  public static void main(String args[]) throws Exception
  {
    LinearSearch ln = new LinearSearch();
    ln.setData();
    ln.putData();
    ln.LinSrch();
  }

}

Vector Demo in Java

Program for vector in java.

Below is the program.

import java.util.*;

class vectorDemo
{
    public static void main(String args[])
    {
        Vector v = new Vector(3,2);

        System.out.println("Intial Size : " + v.size());
        System.out.println("Intial Capacity : " + v.capacity());

        v.addElement(new Integer(1));
        v.addElement(new Integer(2));
        v.addElement(new Integer(3));
        v.addElement(new Integer(4));

        System.out.println("Capacity after 4 additions : " + v.capacity());
        v.addElement(new Double(4.55));
        System.out.println("Capacity after adding double element : " + v.capacity());       
    }
}

Array Keys and Array Values

Below is Simple Example which shows how the array keys or array values can be obtained from a array.


<?php

     $personinfo=array(array("name"=>"john","address"=>"pune","age"=>30),
          array("name"=>"Sathya","address"=>"Nashik","age"=>39),
          array("name"=>"madhav","address"=>"pune","age"=>22));

      $arr1=array_keys($personinfo);

      $arr2=array_values($personinfo);

       echo "OUTPUT AS ONLY KEYS FOR GIVEN ARRAY";
       echo "<br><br>";
       print_r($arr1);

      echo "<br><br>";   
      echo "OUTPUT AS ONLY VALUES FOR GIVEN ARRAY";
      echo "<br><br>";
      print_r($arr2);

?>

PHP Function to create slug from string

Here is simple Function to create slug from string.

function getSlug($title)

             {

                        $slug = preg_replace("/[^a-zA-Z0-9 ]/", "", $title);

                           $slug = str_replace(" ", "-", $slug);

                        $slug=strtolower($slug);

                        return($slug); 

  }

PHP Function to generate random unique string.

Here is a Simple Function to generate random unique string.

            function GenerateNumber($min, $max)

{

                        // Create the meta-password

                        $sMetaPassword = "";

                        global $CONFIG;

                        $ahPasswordGenerator = array(

                        "C" => array('characters' => 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ', 'minimum' => $min, 'maximum' => $max),

//"S" => array('characters' => "!@()-_=+?*^&", 'minimum' => 2, 'maximum' => 2

"N" => array('characters' => '1234567890', 'minimum' => $min, 'maximum' => $max)

);

                        foreach ($ahPasswordGenerator as $cToken => $ahPasswordSeed)

$sMetaPassword .= str_repeat($cToken, rand($ahPasswordSeed['minimum'], $ahPasswordSeed['maximum']));

                                    $sMetaPassword = str_shuffle($sMetaPassword);

                        // Create the real password

                        $arBuffer = array();

                        for ($i = 0; $i < strlen($sMetaPassword); $i ++)

$arBuffer[] = $ahPasswordGenerator[(string)$sMetaPassword[$i]]['characters'][rand(0, strlen($ahPasswordGenerator[$sMetaPassword[$i]]['characters']) - 1)];

                        return implode("", $arBuffer);

} 

PHP Function to check whether the given number is decimal or not.

Below is a simple Function to check whether the given number is decimal or not.

function check_decimal($dec_val, $decimals = 2)

{

                        $pattern = "/^[-]*[0-9][0-9]*\.[0-9]{".$decimals."}$/";

                        if (preg_match($pattern,  $dec_val))

                                    return true;

                        else

                                    return false;

}

PHP Function to check whether a given date is valid or not.

Here is a Simple Function to check whether a given date is valid or not.

           function is_valid_date($value, $separator='-')

{

              if(strlen($value) <= 10)

                        {

                        // check date

                        $arr=explode($separator,$value);

                        $day=$arr[2];

                        $month=$arr[1];

                        $year=$arr[0];

                        if(@checkdate($month, $day, $year))

                                    return true;

              }

             return false;

}

PHP Function to calculate days difference between given 2 dates.

Here is a simple  Function to calculate days difference between given 2 dates.

function daysDifference($endDate, $beginDate)

{

              //explode the date by "-" and storing to array

             $date_parts1=explode("-", $beginDate);

             $date_parts2=explode("-", $endDate);

             //gregoriantojd() Converts a Gregorian date to Julian Day Count

            $start_date=gregoriantojd($date_parts1[1], $date_parts1[2], $date_parts1[0]);

             $end_date=gregoriantojd($date_parts2[1], $date_parts2[2], $date_parts2[0]);

             return $end_date - $start_date;

}

PHP Function to convert date from mm/dd/yyyy to yyyy-mm-dd

Here is a simple Function to convert date from  mm/dd/yyyy to yyyy-mm-dd.

function convert_date($date)

{

                        if($date=='')

                        return '';

                     else

                        $dateArray=explode('/',$date);

                        return "$dateArray[2]-$dateArray[0]-$dateArray[1]";

}

PHP Function to validate an email address

Here is a simple Function to validate an email address in php.

function check_email($mail_address)

{

                        if($mail_address == '')

                        {

                                    return false;

                        }

                        else

                        {

if (preg_match("/^[0-9a-z]+(([\.\-_])[0-9a-z]+)*@[0-9a-z]+(([\.\-])[0-9a-z-]+)*\.[a-z]{2, 4}$/i",  strtolower($mail_address)))

                                    return true;

                        else

                                    return false;

                        }

}

PHP Function to get extension of a file.

Here is a simple function which returns the extension of the file.

           function getExtension($str)

{

                        $i = strrpos($str,".");

                        if (!$i) { return ""; }

                        $l = strlen($str) - $i;

                        $ext = substr($str,$i+1,$l);

                        return $ext;

}