Java中常见的语法糖分享

List<String> list = Arrays.asList("apple", "banana", "orange");
for (String fruit : list) {
    System.out.println(fruit);
}

List<String> list = Arrays.asList("apple", "banana", "orange");
Iterator<String> iterator = list.iterator();
while (iterator.hasNext()) {
    String fruit = iterator.next();
    System.out.println(fruit);
}

int num = 10;
Integer number = num; // 自动装箱
int result = number + 5; // 自动拆箱

int num = 10;
Integer number = Integer.valueOf(num); // 手动装箱
int result = number.intValue() + 5; // 手动拆箱

public void printNumbers(int... numbers) {
    for (int num : numbers) {
        System.out.println(num);
    }
}
printNumbers(1, 2, 3); // 输出：1 2 3

public void printNumbers(int[] numbers) {
    for (int num : numbers) {
        System.out.println(num);
    }
}
printNumbers(new int[]{1, 2, 3}); // 输出：1 2 3

try (BufferedReader reader = new BufferedReader(new FileReader("file.txt"))) {
    String line;
    while ((line = reader.readLine()) != null) {
        System.out.println(line);
    }
} catch (IOException e) {
    e.printStackTrace();
}

BufferedReader reader = null;
try {
    reader = new BufferedReader(new FileReader("file.txt"));
    String line;
    while ((line = reader.readLine()) != null) {
        System.out.println(line);
    }
} catch (IOException e) {
    e.printStackTrace();
} finally {
    if (reader != null) {
        try {
            reader.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}