使用 for 循环遍历数组 - 一直失败？

Question

(这里是你好世界级测试器) 我有一个 java 应用程序来删除一堆文件后测试以保持一切干净，但问题是我似乎无法让它工作，这是我第一次接触数组，它稍微复杂一些比他们在教程中展示的那些，任何帮助将不胜感激。

    String[] fileArray;
    fileArray = new String[8];

    fileArray[0] = "/Downloads/file1.csv";
    fileArray[1] = "/Downloads/file2.csv";
    fileArray[2] = "/Downloads/file3.csv";
    fileArray[3] = "/Downloads/file4.csv";
    fileArray[4] = "/Downloads/file5.csv";
    fileArray[5] = "/Downloads/file6.csv";
    fileArray[6] = "/Downloads/file7.csv";
    fileArray[7] = "/Downloads/file8.csv";

    String home = System.getProperty("user.home");
    File filePath = new File(home+fileArray); 
    System.out.println(filePath);

    for (String count: fileArray) {
    if (filePath.exists()) {
        filePath.delete();
        System.out.println("Deleted");
    }
    else
    {
        System.out.println("failed");
        Assert.fail();
    }
    System.out.println(count);
    }

Answer 1

您应该为数组中的每个元素连接新的文件路径，因此需要在for 正文中处理文件。因此，在每次迭代中，您都会进入变量filePath 数组的下一个元素，然后您需要将此变量连接到基本路径home + filePath。现在您正在查看所需的文件，您可以创建 file 对象并使用它。

String[] fileArray;
fileArray = new String[8];

fileArray[0] = "/Downloads/file1.csv";
fileArray[1] = "/Downloads/file2.csv";
fileArray[2] = "/Downloads/file3.csv";
fileArray[3] = "/Downloads/file4.csv";
fileArray[4] = "/Downloads/file5.csv";
fileArray[5] = "/Downloads/file6.csv";
fileArray[6] = "/Downloads/file7.csv";
fileArray[7] = "/Downloads/file8.csv";

String home = System.getProperty("user.home");


for (String filePath: fileArray) {
    File file = new File(home + filePath); 
    System.out.println(filePath);
    if (file.exists()) {
        file.delete();
        System.out.println("Deleted");
    } else {
        System.out.println("failed");
        Assert.fail();
    }
}

您似乎希望在变量count 中您会看到许多迭代文件。在这种情况下，它不会像这样工作。这种for 的形式如下所示：for (String arrayElement : arrayToWorkWith) - 意味着在变量arrayElement 的每次迭代中，将放入数组arrayToWorkWith 中的下一个元素。如果您需要在迭代期间计算元素的数量，您可以引入单独的变量并增加它或使用另一种形式的 for 循环 - for (int i = 0; i < fileArray.length; i++)。

Answer 2

试试这个方法

 String[] fileArray;
    fileArray = new String[8];

    fileArray[0] = "/Downloads/file1.csv";
    fileArray[1] = "/Downloads/file2.csv";
    fileArray[2] = "/Downloads/file3.csv";
    fileArray[3] = "/Downloads/file4.csv";
    fileArray[4] = "/Downloads/file5.csv";
    fileArray[5] = "/Downloads/file6.csv";
    fileArray[6] = "/Downloads/file7.csv";
    fileArray[7] = "/Downloads/file8.csv";

    String home = System.getProperty("user.home");
    //File filePath = new File(home+fileArray);  thats wrong here and will give you a invalid file anyway as you concatenating a string with an object


    for (String file: fileArray) {
    File filePath = new File(home+file); //here you need to define the file
    if (filePath.exists()) {
        filePath.delete();
        System.out.println("Deleted");
    }
    else
    {
        System.out.println("failed");
        Assert.fail();
    }
    System.out.println(file);
    }