Java 字符串拆分不起作用

Question

Java 专家，

请查看下面的拆分命令代码，让我知道为什么最后两个空值没有被捕获。

String test = "1,O1,,,,0.0000,0.0000,,";
String[] splittest = test.split(",");
System.out.println("length -"+splittest.length);
for (String string : splittest) {
    System.out.println("value"+string);
}

我得到的结果

length -7
value1
valueO1
value
value
value
value0.0000
value0.0000

令人惊讶的是，长度是 7，而它应该是 9，而且您可以看到 0.0000 之后的值，即最后两个空值不会出现。让我们说如果我改变字符串测试“1,O1,,,,0.0000,0.0000,0,0”

String test = "1,O1,,,,0.0000,0.0000,0,0";
String[] splittest = test.split(",");
System.out.println("length -"+splittest.length);
for (String string : splittest) {
    System.out.println("value"+string);
}

我做对了

length -9
value1
valueO1
value
value
value
value0.0000
value0.0000
value0
value0

我不认为我做错了。这是一个错误吗？ JAVA版本-jdk1.6.0_31

Answer 1

它的行为与 the javadoc 中指定的一样:

This method works as if by invoking the two-argument split method with the given expression and a limit argument of zero. Trailing empty strings are therefore not included in the resulting array.

如果你想保留尾随的空白字符串，你可以使用 2 argument split method负限制:

String[] splittest = test.split(",", -1);

If the limit is non-positive then the pattern will be applied as many times as possible and the array can have any length.