34 lines
894 B
Java
34 lines
894 B
Java
// references/MutableInteger.java
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// (c)2021 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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// A changeable wrapper class
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import java.util.*;
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import java.util.stream.*;
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class IntValue {
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private int n;
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IntValue(int x) { n = x; }
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public int getValue() { return n; }
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public void setValue(int n) { this.n = n; }
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public void increment() { n++; }
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@Override public String toString() {
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return Integer.toString(n);
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}
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}
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public class MutableInteger {
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public static void main(String[] args) {
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List<IntValue> v = IntStream.range(0, 10)
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.mapToObj(IntValue::new)
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.collect(Collectors.toList());
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System.out.println(v);
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v.forEach(IntValue::increment);
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System.out.println(v);
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}
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}
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/* Output:
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[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
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[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
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*/
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