stream foreach

import java.util.Arrays;
import java.util.List;

public class StreamForEachExample {
    public static void main(String[] args) {
        List<String> names = Arrays.asList("Alice", "Bob", "Charlie");

        // 使用 forEach 遍历并打印每个名字
        names.stream().forEach(name -> System.out.println(name));
    }
}

import java.util.concurrent.ConcurrentHashMap;
import java.util.Map;

public class ConcurrentModificationExample {
    public static void main(String[] args) {
        Map<String, String> map = new ConcurrentHashMap<>();
        map.put("1", "Alice");
        map.put("2", "Bob");

        map.forEach((key, value) -> {
            if (key.equals("1")) {
                map.put("3", "Charlie"); // 不会抛出异常
            }
        });
    }
}

import java.util.List;

public class ParallelStreamExample {
    public static void main(String[] args) {
        List<Integer> numbers = Arrays.asList(1, 2, 3, 4, 5, 6, 7, 8, 9, 10);

        // 使用并行流计算总和
        int sum = numbers.parallelStream().mapToInt(Integer::intValue).sum();
        System.out.println("Sum: " + sum);
    }
}