50 lines
1.4 KiB
Java
50 lines
1.4 KiB
Java
// arrays/CollectionComparison.java
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// (c)2016 MindView LLC: see Copyright.txt
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// We make no guarantees that this code is fit for any purpose.
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// Visit http://mindviewinc.com/Books/OnJava/ for more book information.
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import java.util.*;
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class BerylliumSphere {
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private static long counter;
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private final long id = counter++;
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@Override
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public String toString() { return "Sphere " + id; }
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}
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public class CollectionComparison {
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public static void main(String[] args) {
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BerylliumSphere[] spheres = new BerylliumSphere[10];
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for(int i = 0; i < 5; i++)
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spheres[i] = new BerylliumSphere();
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System.out.println(Arrays.toString(spheres));
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System.out.println(spheres[4]);
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List<BerylliumSphere> sphereList= new ArrayList<>();
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for(int i = 0; i < 5; i++)
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sphereList.add(new BerylliumSphere());
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System.out.println(sphereList);
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System.out.println(sphereList.get(4));
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int[] integers = { 0, 1, 2, 3, 4, 5 };
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System.out.println(Arrays.toString(integers));
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System.out.println(integers[4]);
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List<Integer> intList = new ArrayList<>(
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Arrays.asList(0, 1, 2, 3, 4, 5));
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intList.add(97);
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System.out.println(intList);
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System.out.println(intList.get(4));
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}
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}
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/* Output:
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[Sphere 0, Sphere 1, Sphere 2, Sphere 3, Sphere 4, null,
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null, null, null, null]
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Sphere 4
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[Sphere 5, Sphere 6, Sphere 7, Sphere 8, Sphere 9]
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Sphere 9
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[0, 1, 2, 3, 4, 5]
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4
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[0, 1, 2, 3, 4, 5, 97]
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4
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*/
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