// This class is a test program for showing that arrays are like objects.

// command: javac IntArrayTest4.java

// command: java IntArrayTest4

import java.util.Arrays;

public class IntArrayTest4 {

// main( )

public static void main (String args[] ) {

int [] ar1 = new int [10];

int [] ar2 = new int [10];

// ar1 and ar2 contain the same values

for (int i=0 ; i < ar1.length; i++) {

ar1[i] = 2*i + i - 20;

}

for (int i=0 ; i < ar2.length; i++) {

ar2[i] = 2*i + i - 20;

}

// Two arrays of the same values are not equal.

if (ar1 == ar2)

System.out.println ("The two arrays are the same.");

else

System.out.println ("The two arrays are not the same.");

if ( ar1.equals(ar2) ) // compared as two objects

System.out.println ("The two arrays are the same.");

else

System.out.println ("The two arrays are not the same.");

if ( Arrays.equals(ar1, ar2) ) // comparison for array contents

System.out.println ("The two arrays have the same values.");

else

System.out.println ("The two arrays have different values.");

System.out.println ("Before assignment ...");

System.out.println ("ar1[3] = " + ar1[3] + "\t\tar2[3] = " + ar2[3]);

ar1=ar2;

// Assigning ar2 to ar1 makes them reference the same object.

if (ar1 == ar2)

System.out.println ("The two arrays are the same.");

else

System.out.println ("The two arrays are not the same.");

if ( ar1.equals(ar2) ) // compared as two objects

System.out.println ("The two arrays are the same.");

else

System.out.println ("The two arrays are not the same.");

if ( Arrays.equals(ar1, ar2) ) // comparison for array contents

System.out.println ("The two arrays have the same values.");

else

System.out.println ("The two arrays have different values.");

System.out.println ("After assignment (before set) ...");

System.out.println ("ar1[3] = " + ar1[3] + "\t\tar2[3] = " + ar2[3]);

ar2[3] = 33333; //Changing ar2[3] will also change ar1[3]

System.out.println ("After set ...");

System.out.println ("ar1[3] = " + ar1[3] + "\t\tar2[3] = " + ar2[3]);

} //main()

} // IntArrayTest2 class