使用 String.split() 循环遍历二维数组

Question

我有一个简单的问题，但我是来自 PHP 的 Java 的新手。 我需要将分隔的文本文件拆分为一个数组。 我把它分解成一系列行，每一行看起来像这样：

{
    {Bob | Smithers | Likes Cats | Doesnt Like Dogs},
    {Jane | Haversham | Likes Bats | Doesnt Like People}
}

我需要把它变成一个二维数组。

在 PHP 中，这是小菜一碟。 您只需使用 explode(); 我尝试在一维数组上使用 String.split，它也没有那么糟糕。 事情是，我还没有学会如何对 Java 好。 所以我不知道如何循环遍历数组并将其变成 2d。 这就是我所拥有的：

for (i = 0; i < array.length; i++) {
    String[i][] 2dArray = array[i].split("|", 4);
}

PHP 将是

for ($i = 0; $i < count($array); $i++) {
    $array[i][] = explode(",", $array[i]);
}

Answer 1

您可以像这样循环数组：

    // Initialize array
    String[] array = {
            "Bob | Smithers | Likes Cats | Doesnt Like Dogs",
            "Jane | Haversham | Likes Bats | Doesnt Like People"
    };

    // Convert 1d to 2d array
    String[][] array2d = new String[2][4];
    for(int i=0;i<array.length;i++) {
        String[] temp = array[i].split(" \\| ");

        for(int j=0;j<temp.length;j++) {
            array2d[i][j] = temp[j];
        }
    }

    // Print the array
    for(int i=0;i<array2d.length;i++) {
        System.out.println(Arrays.toString(array2d[i]));
    }

注意：我使用\\\\| 分割管道字符。

Answer 2

问题

如果我答对了，您将输入以下内容：

{{Bob | Smithers | Likes Cats | Doesnt Like Dogs},{Jane | Haversham | Likes Bats | Doesnt Like People}}

可读版本：

{
    {Bob | Smithers | Likes Cats | Doesnt Like Dogs},
    {Jane | Haversham | Likes Bats | Doesnt Like People}
}

您想用二维String Aray String[][]表示该结构。

---

解

关键是String#split方法，该方法将给定的String拆分为由给定符号分隔的子字符串。 这是,和| 在您的示例中。

首先，我们删除所有{ ， }因为我们不需要它们（只要文本本身不包含定界符）：

String input = ...
String inputWithoutCurly = input.replaceAll("[{}]", "");

现在的文本是：

Bob | Smithers | Likes Cats | Doesnt Like Dogs,Jane | Haversham | Likes Bats | Doesnt Like People

接下来我们要创建阵列，由分裂的外形尺寸, ：

String[] entries = inputWithoutCurly.split(",");

现在的结构是：

[
    "Bob | Smithers | Likes Cats | Doesnt Like Dogs",
    "Jane | Haversham | Likes Bats | Doesnt Like People"
]

现在，我们希望将每个内部文本拆分为各个部分。 因此，我们迭代所有条目，并用|分隔它们| 并将它们收集为结果：

// Declaring a new 2-dim array with unknown inner dimension
String[][] result = new String[entries.length][];

// Iterating all entries
for (int i = 0; i < entries.length; i++) {
    String[] data = entries[i].split(" | ");

    // Collect data to result
    result[i] = data;
}

最后，我们具有所需的结构：

[
    [ "Bob", "Smithers", "Likes Cats", "Doesnt Like Dogs" ],
    [ "Jane", "Haversham", "Likes Bats", "Doesnt Like People"]
]

一切紧凑：

String[] entries = input.replaceAll("[{}]", "").split(",");
String[][] result = new String[entries.length][];

for (int i = 0; i < entries.length; i++) {
    result[i] = entries[i].split(" | ");
}

---

流

如果您具有Java 8或更高版本，则可以使用Stream API以获得紧凑的功能样式：

String[][] result = Arrays.stream(input.replaceAll("[{}]", "").split(","))
    .map(entry -> entry.split(" | "))
    .toArray(String[][]::new);

Answer 3

我确实有一个类似的问题陈述与二维数组中的 csv 块：我想展平这个列表并创建一个单独的 csv 字符串：输入以下格式：[[sourcePKey，firstName，lastName，fullName，title，designation9，birthDate pkeyMultiValueBulk1 kk, , dNGDHA, RtUURv, 01-01-2020 pkeyMultiValueBulk200, kk, , dNGDHA, RtUURv, 02-01-2020 pkeyMultiValueBulk201, Kishlay, Kishore, , dNGDHA, RtUURv, 03-01-2020 pkeyMultiValueBulk202, Kishlay, Kishore,, , RtUURv, 04-01-2020 pkeyMultiValueBulk203, Kishlay, Kishore, , dNGDHA, RtUURv, 05-01-2020 pkeyMultiValueBulk204, Kishlay, Kishore, , dNGDHA, RtUURv, 06-01-2020 pkeyMultiValueBulk205, Kishlay, Kishore, , RtNGDHA , 07-01-2020 pkeyMultiValueBulk206, Kishlay, Kishore, , dNGDHA, RtUURv, 08-01-2020 pkeyMultiValueBulk207, Kishlay, Kishore, , dNGDHA, RtUURv, 09-01-2020 ], [pkeyMultiValueBulk208, Kishlay, Kishore, , dNGDHA, RtUURv，10-01-2020 pkeyMultiValueBulk209，基什莱，基什矿石, , dNGDHA, RtUURv, 11-01-2020 pkeyMultiValueBulk210, Kishlay, Kishore, , dNGDHA, RtUURv, 12-01-2020 pkeyMultiValueBulk211, Kishlay, Kishore, , dNGDHA, RtUURv, 13-01-2020 pkeyMultiValueBulk212, Kishore, , dNGDHA, RtUURv, 14-01-2020 pkeyMultiValueBulk213, Kishlay, Kishore, , dNGDHA, RtUURv, 15-01-2020 pkeyMultiValueBulk214, Kishlay, Kishore, , dNGDHA, RtUURv, 16-01-2020 pkeyMultiValueBulk215, Kishlay, Kishore, , RtUURv, 17-01-2020 pkeyMultiValueBulk216, Kishlay, Kishore, , dNGDHA, RtUURv, 18-01-2020 pkeyMultiValueBulk217, Kishlay, Kishore, , dNGDHA, RtUURv, 19-01-2020] ]

所需的 Output：源 PKey,firstName,lastName,fullName,title,designation,birthDate pkeyMultiValueBulk199,Kishlay,Kishore,,dNGDHA,RtUURv,01-01-2020 pkeyMultiValueBulk200,Kishlay,Kishore,Multi02-020-210URv Kishlay,Kishore,,dNGDHA,RtUURv,03-01-2020 pkeyMultiValueBulk202,Kishlay,Kishore,,dNGDHA,RtUURv,04-01-2020 pkeyMultiValueBulk203,Kishlay,Kishore,,dNGDHA,RtUURv,05-01-2020 pkeyMultiValueBulk204,Kishlay, Kishore,,dNGDHA,RtUURv,06-01-2020 pkeyMultiValueBulk205,Kishlay,Kishore,,dNGDHA,RtUURv,07-01-2020 pkeyMultiValueBulk206,Kishlay,Kishore,,dNGDHA,RtUURv,08-01-2020