25 lines
969 B
Java
25 lines
969 B
Java
// collections/AddingGroups.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://OnJava8.com for more book information.
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// Adding groups of elements to Collection objects
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import java.util.*;
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public class AddingGroups {
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public static void main(String[] args) {
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Collection<Integer> collection =
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new ArrayList<>(Arrays.asList(1, 2, 3, 4, 5));
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Integer[] moreInts = { 6, 7, 8, 9, 10 };
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collection.addAll(Arrays.asList(moreInts));
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// Runs significantly faster, but you can't
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// construct a Collection this way:
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Collections.addAll(collection, 11, 12, 13, 14, 15);
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Collections.addAll(collection, moreInts);
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// Produces a list "backed by" an array:
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List<Integer> list = Arrays.asList(16,17,18,19,20);
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list.set(1, 99); // OK -- modify an element
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// list.add(21); // Runtime error; the underlying
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// array cannot be resized.
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}
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}
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