Arrays in JAVA

An array is a very common type of data structure where in all elements must be of the same data type.Once defined , the size of an array is fixed and cannot increase to accommodate more elements.

x[0]=0;
x[1]=1;
x[2]=2;
x[3]=3;
x[4]=4;
x[5]=5;

Using and array in your program is a 3 step process -
1) Declaring your Array
2) Constructing your Array
3) Initializing your Array Syntax for Declaring Array Variables is

int intArray[];
 // Defines that intArray is an ARRAY variable which will store integer values
int []intArray;

Constructing an Array

intArray = new int[10]; // Defines that intArray will store 10 integer values

Declaration and Construction combined

int intArray[] = new int[10];

Initializing an Array

intArray[0]=1; // Assigns an integer value 1 to the first element 0 of the array
 
intArray[1]=2; // Assigns an integer value 2 to the second element 1 of the array

Declaring and Initializing an Array

int intArray[] = {1, 2, 3, 4};
// Initilializes an integer array of length 4 where the first element is 1 , second element is 2 and so on.

Multidimensional Array To declare a multidimensional array variable, specify each additional index using another set of square brackets.

int twoD[ ][ ] = new int[4][5] ;

When you allocate memory for a multidimensional array, you need only specify the memory for the first (leftmost) dimension. You can allocate the remaining dimensions separately. In Java the length of each array in a multidimensional array is under your control.

int twoD[][] = new int[4][];
 
twoD[0] = new int[5];
 
twoD[1] = new int[6];
 
twoD[2] = new int[7];
 
twoD[3] = new int[8];

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Faces behind popular Programming Languages

1. Java (James Gosling)

2. C (Ken Thompson Left & Dennis Ritchie Right)

3. C++ (Bjarne Stroustrup)

4. Python (Guido van Rossum )

5. Fortran (John W. Backus)

6. Linux Kernel (Linus Benedict Torvalds)

7. Perl (Larry Wall)

8. C# (Development team led by Anders Hejlsberg)

9. Ruby (Yukihiro Matsumoto)

10. Ruby on Rails (RoR) (David Heinemeier Hansson)

11. JavaScript (Brendan Eich)

12. PHP (Rasmus Lerdorf)

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Compare Images In Java

package defaultt;

import java.awt.image.BufferedImage;
import java.awt.image.DataBuffer;
import java.io.File;

import javax.imageio.ImageIO;

public class CompareImage {
 public static boolean compareImage(File fileA, File fileB) {        
     try {
         // take buffer data from botm image files //
         BufferedImage biA = ImageIO.read(fileA);
         DataBuffer dbA = biA.getData().getDataBuffer();
         int sizeA = dbA.getSize();                      
         BufferedImage biB = ImageIO.read(fileB);
         DataBuffer dbB = biB.getData().getDataBuffer();
         int sizeB = dbB.getSize();
         // compare data-buffer objects //
         if(sizeA == sizeB) {
             for(int i=0; i<sizeA; i++) { 
                 if(dbA.getElem(i) != dbB.getElem(i)) {
                     return false;
                 }
             }
             return true;
         }
         else {
             return false;
         }
     } 
     catch (Exception e) { 
         System.out.println("Failed to compare image files ...");
         return  false;
     }
 }
 
 public static void main(String[] args) {
  File a = new File("F:\\uu.jpg");
  File b = new File("F:\\uu.jpg");
  boolean flag = compareImage(a, b);
  
  System.out.println("Match: "+flag);
 }
}

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