21 lines
606 B
Java
21 lines
606 B
Java
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package stream;
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import java.util.Arrays;
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import java.util.List;
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import java.util.Optional;
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public class StreamExample06 {
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public static void main(String[] args) {
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List<Integer> numbers = Arrays.asList(1, 2, 3, 4, 5);
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// 使用 reduce 求和
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Optional<Integer> sum = numbers.stream()
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.reduce(Integer::sum);
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sum.ifPresent(System.out::println); // 输出: 15
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// 使用带初始值的 reduce
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int sumWithIdentity = numbers.stream()
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.reduce(0, Integer::sum);
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System.out.println(sumWithIdentity); // 输出: 15
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}
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}
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