Java优学网数组遍历教程：从基础到实战，轻松掌握高效遍历技巧

for (int i = 0; i < array.length; i++) {

// 处理array[i]

}

int[] numbers = {1, 2, 3, 4, 5}; for (int i = 0; i < numbers.length; i++) {

System.out.println("索引 " + i + " 的值是: " + numbers[i]);

}

int[] numbers = {1, 2, 3, 4, 5}; IntStream stream = Arrays.stream(numbers);

int[][] matrix = {

{1, 2, 3},
{4, 5, 6},
{7, 8, 9}

};

for (int i = 0; i < matrix.length; i++) {

for (int j = 0; j < matrix[i].length; j++) {
    System.out.print(matrix[i][j] + " ");
}
System.out.println(); // 换行，让输出更美观

}

int[] numbers = {1, 2, 3}; // 错误：索引从0开始，最大有效索引是2 System.out.println(numbers[3]); // 抛出异常

// 原始版本 - 执行时间约1200ms for (int i = 0; i < productIds.length; i++) {

Product product = productService.findById(productIds[i]);
if (product != null && product.isAvailable()) {
    availableProducts.add(product);
}

}