string - 在 Scala : Missing Trailing Empty Strings? 中拆分逗号分隔的字符串

Question

我有一个 csv 格式的数据文件。
我正在尝试使用基本拆分命令 line.split(',') 拆分每一行
但是当我得到这样的字符串时 "2,," ,
而不是像这样返回一个数组 Array(2,"","")我刚收到一个 Array: Array(2) .
我绝对错过了一些基本的东西，有人可以帮助指出在此处拆分逗号分隔字符串的正确方法吗？

Answer 1

这是从Java继承的。您可以使用 split(String regex, int limit) 实现您想要的行为。重载:

"2,,".split(",", -1) // = Array(2, "", "")

请注意 String而不是 Char .

正如 Java Docs 所解释的，limit参数使用如下:

The limit parameter controls the number of times the pattern is applied and therefore affects the length of the resulting array. If the limit n is greater than zero then the pattern will be applied at most n - 1 times, the array's length will be no greater than n, and the array's last entry will contain all input beyond the last matched delimiter. If n is non-positive then the pattern will be applied as many times as possible and the array can have any length. If n is zero then the pattern will be applied as many times as possible, the array can have any length, and trailing empty strings will be discarded.

Source

使用 split(separator: Char)将使用 limit 调用上面的重载零。